Brushing aside the obstacles of Victor Valdés and the stadium sprinklers, José Mourinho sprinted across the Camp Nou pitch, his arm aloft in celebration as he looked to locate the pocket of Italian fans who had made the trip across the Mediterranean. The Internazionale manager had just inflicted the pain of defeat on Barcelona and was determined to demonstrate just how much satisfaction triumph over the Catalans had provided him.

The scene was reminiscent of one that had taken place five years earlier in 2005. Mourinho, cloaked in his grey trench coat, strode across the Stamford Bridge turf with a clenched fist raised to salute the home supporters. The Chelsea boss had just witnessed his side overcome Barcelona in a tie that produced managerial mind games, tunnel fracases, allegations of skullduggery, controversial red cards, stunning goals and, sadly, heinous death threats.

Previously, a second-round Champions League fixture between Chelsea and Barcelona would not have carried the level of hype and expectation that had grown in the lead up to this encounter. It was the events of the summer in 2003, though, that had set the clubs on a continental collision course as they underwent a revolution in their respective quests to establish themselves as the number one force in European football.

Barcelona had been floundering since the turn of the millennium. Failure to land silverware in any competition since 1999, Los Cules’ barren run coincided with several disastrous managerial and player recruits as Real Madrid, Deportivo and Valencia left the Catalan giants in the shadows in LaLiga.

It took the arrival of Joan Laporta, a Catalan lawyer who won the club presidential elections that summer, to change the fortunes of the club. Laporta’s first significant moves were to bring in Frank Rijkaard as head coach and secure the signing of Brazilian superstar Ronaldinho from Paris Saint-Germain. Following a difficult start, Rijkaard had taken a struggling patchwork of a team and moulded them back into contention for LaLiga by the end of his first season in charge.

Convinced of his abilities, the Barcelona board of directors handed the Dutchman license to shape the squad as he saw fit. The incoming Samuel Eto’o, Ludovic Giuly and Deco provided pace and creativity to a squad that had grown stale, their arrivals spelling the end for older players such as Patrick Kluivert, Marc Overmars and Edgar Davids, who departed the Camp Nou.

As with their opponents across the English channel, Barcelona were in contention for the 2004/05 league title. However, they weren’t quite as convincing in European football, finishing runners up in their group behind Carlo Ancelotti’s AC Milan side that would go on to reach the final.

Meanwhile, in west London, Russian billionaire Roman Abramovich had purchased Chelsea, who suddenly had the wealthiest owner in world football at their helm. That first summer alone saw the Russian invest £130m on new signings in an attempt to transform Chelsea into a significant global force. While the riches of Abramovich wasn’t quite enough to lure superstars from the highest echelons of the game, Chelsea still proved to be an attractive enough proposition for the likes of Joe Cole, Damien Duff and, perhaps most crucially, Claude Makélélé from Real Madrid.

Read | Frank Rijkaard: the reluctant one

Improvement in performances on the field was apparent almost immediately as Claudio Ranieri guided his team to a European semi-final, where they would crash out to Monaco. It was common knowledge, however, that Abramovich considered the Italian unsuitable for the role on a long-term basis and it was a surprise to nobody when he ruthlessly disposed of Ranieri.

Abramovich was a man accustomed to the finer things in life and, in the summer of 2004, no coach in world football represented a more attractive proposition than Mourinho. The 41-year-old from Setúbal had just won the Champions League with Porto and arrived at Stamford Bridge as a charismatic, multilingual, meticulous tactician who had complete confidence in his coaching abilities.

The Portuguese utilised the vast riches at his owner’s disposal to attract players who shared his hunger, and who also had their best playing years ahead of them. Mourinho disposed of the likes of Juan Sebastián Verón and Hernán Crespo, and in came players he was already familiar with from Portugal such as Ricardo Carvalho, Paulo Ferreira and Tiago, in addition to Petr Čech, Arjen Robben and Didier Drogba.

Mourinho’s impact was immediate, and Chelsea would soon lead the Premier League as his team adopted a solid defensive structure that helped them claim victory in the majority of fixtures. Mourinho’s tactical nous also proved to be effective in the Champions League as Chelsea strolled through the group stage to see them top their table ahead of PSG, CSKA Moscow and Porto.

When the two teams were drawn against each other in the first knockout round, a fascinating clash of styles lay in prospect. The prevailing perception was that this would be a story of Barcelona’s devastating attacking talents attempting to break down the stubborn and disciplined Chelsea backline. However, it would be simplistic to label the tie as merely a duel between attack versus defence.

Barcelona’s back line was constructed of players of the calibre of Rafael Márquez and Carles Puyol, while Chelsea were capable of producing outstanding attacking performances with Frank Lampard’s bursting runs into the box and Robben’s trickery on the wing supporting the imposing presence of Drogba.

The first leg would take place in Barcelona, and Mourinho wasted little time in instigating the pre-match psychological battle. The former Benfica boss, never shy in airing his criticisms of fellow managers, praised Rijkaard’s great playing career while simultaneously downplaying the Dutchman’s managerial achievements, reminding everyone of the fact that he had “won lots of trophies while Rijkaard had won zero”.

Then, in his final press conference before the match, the self-assured Mourinho addressed speculation regarding the Chelsea line-up by listing the 11 players he intended to start with before confidently predicting the teamsheet of his Spanish opponents and getting up and departing the room.

Read | José Mourinho: the early years

The return of Mourinho to Catalonia had added extra intrigue to the occasion. The Portuguese had been a popular figure during his time at the club where he worked as an assistant under Bobby Robson and then latterly Louis van Gaal. Now, five years after his departure, the man the Blaugrana once knew as “the translator” would strut back into the Camp Nou as a dashing, dynamic and successful Champions League-winning manager who had at the football world at his mercy.

Rijkaard, a usually placid character, was clearly irritated at Mourinho’s attempts at forcing him to second-guess himself. While the Barcelona boss respected Mourinho’s considerable achievements, he failed to share the same enthusiasm for the playing style that had bought him that success. In what might be interpreted as a backhanded compliment, the Dutchman said of Chelsea in a pre-match interview with The Guardian, “They’re a great team, a great team. Very functional.”

The appointment of Rijkaard had proven to be an inspired move from Laporta, even if there were some initial doubts. Although the former Ajax man followed in the footsteps of legendary Dutch figures Rinus Michels and Johan Cruyff to manage the club, he had arrived following a spell at Sparta Rotterdam where he had led them to relegation for the first time in their history.

Following the poor start to his first campaign in charge, Rijkaard’s relaxed coaching style gradually encouraged his players to enjoy themselves on the pitch, and it was this approach that set the Catalans up for future glory. Almost the polar opposite of Mourinho, Rijkaard was a cool presence on the touchline. Puyol said of him: “The best thing about the mister is that he is very calm. He gives us freedom and doesn’t always pressure us.”

Under the floodlights of Barcelona’s grand cathedral, the early stages of the first leg began as most predicted. Barcelona, with Xavi and Deco orchestrating from midfield, attacked from the outset as they looked to break down Chelsea’s formidable defence early on. Ronaldinho was the main protagonist in the search for an early lead, first curling just wide before laying on a chance for Eto’o who blazed over the bar.

Chelsea, meanwhile, absorbed the Barça pressure, waiting for an opportunity to counter-attack, and their patience was rewarded on 33 minutes when Lampard sent Duff clear down the right. With what seemed like acres of Camp Nou turf ahead of him, the Irish winger ran toward the byline before crossing into the box where Juliano Belletti turned the ball into the Barcelona net to gift Mourinho’s side a vital away goal.

With the first half drawing to a close, Mourinho’s tactics were seemingly going according to plan. The onus was on Barcelona to press forward to an even greater extent, which in theory would leave Chelsea further space in which to attack on the break. Early into the second half, however, Mourinho’s plans would be thrown into disarray.

A late tackle by Drogba on Valdés saw the Ivorian sent off for a second booking and Chelsea had lost their focal point who could hold the ball up to help relieve pressure on the defence. While the sending off may have upset Mourinho’s game plan, the repercussions of Drogba’s dismissal would hold greater severity for referee Anders Frisk.

Read | How a selfless Ludovic Giuly helped revive a broken Barcelona

On 66 minutes, following relentless pressure from the home side, Argentine striker Maxi López finally put Barcelona back on level terms. López, who had arrived from River Plate, endured a frustrating time in his short stay at Barcelona but on his Champions League debut had shaken off William Gallas to rifle a shot into the far corner.

Andrés Iniesta was introduced to proceedings in the second half, and the young maestro was majestic as he created a myriad of shooting opportunities for himself. Chelsea struggled to hold on as Barcelona continued to pile forward, and soon the Catalans were to be rewarded for their persistence. Once again, López was instrumental as the Argentine’s mishit strike skid across the penalty box to find Eto’o, who converted first time to ignite a mighty roar from the 89,000 in attendance.

Eto’o was a hard-working, prolific striker who provided so much more than goals with his tireless running into the channels. The Cameroonian had arrived in Spain after signing for Real Madrid before spending short spells at Leganés and then Espanyol. After a stuttering start to life in Spain, Eto’o eventually settled at Real Mallorca. Five successful years on the Balearic island attracted the attention of Barcelona, and he would go on to become one of the vital components in the club’s recent success as he linked up superbly with Ronaldinho, and then in later years with Lionel Messi and Thierry Henry.

Rijkaard, presumably sensing that such a narrow victory may not be enough to see off Chelsea in the tie, commanded his team forward as they searched for a crucial third goal, though chance after chance came and went before Frisk blew the final whistle. Barcelona had won the battle but Chelsea were still very much in the war, and it was arguably Mourinho who could be considered happier with the result, having withstood a bombardment of Barcelona attacks for almost half the match.

If Mourinho had been content with the night’s work, however, he failed to offer any hint of happiness as he addressed the media post-match. The Portuguese, angry with the Drogba decision, suggested that he had seen Rijkaard enter referee Frisk’s dressing room during the interval. Outraged at the prospect of a private conversation between the Barcelona manager and the official during such an intense and vital fixture riled Chelsea enough to put an official complaint into UEFA.

Mourinho’s allegations were unfounded as Rijkaard confirmed he had only approached Frisk in the tunnel to enquire why Chelsea’s goal had stood as he believed Duff to have been offside. By that stage, though, irreparable damage had already been inflicted to the Swedish official’s reputation in the eyes of some angry Chelsea supporters.

The questioning of Frisk’s integrity would lead to death threats being delivered to the Swede over the weeks that followed, unnerving the referee to the point that he retired from officiating. Mourinho would be labelled “an enemy of football” by the chairman of UEFA’s referee commission Volker Roth. While it would be unfair to lay the entirety of the blame at Mourinho’s door, the despicable treatment that Frisk was subjected to was an early example of the controversy that would cast a shadow over Mourinho’s achievements in the game.

Read | Frank Lampard, Didier Drogba and the goals that turned Chelsea into England’s best team

Following the animosity that had been generated from the match in Barcelona, the build-up to the second leg was intense, with Mourinho now firmly cast as the villain in the eyes of Barcelona supporters. There was no love lost between the managers either, and the Frisk incident had been the first time since arriving in England that the Machiavellian side of Mourinho’s character had surfaced. These factors added an extra edge to what had already been an eagerly anticipated contest.

Chelsea, without the suspended Drogba, would switch formations with Mateja Kezman starting alongside Eidur Gudjohnsen in a front two. Iniesta, meanwhile, who had caused Chelsea so many problems in the first leg, was handed a starting berth for Barcelona. With Barcelona leading the tie and Chelsea requiring only one goal to go through, a tight, cagey affair was forecast.

On a cold, late winter night in west London, though, an astounding match would unfold. If the Stamford Bridge crowd were expecting Chelsea to keep the game tight before snatching a goal, they would be stunned by a breathtaking start from their team.

Eight minutes in, Lampard sent Kežman clear down the right. The Serbian striker glanced inside, where he saw Gidjohnsen bursting to get into the box. A first time ball from Kežman found the Icelandic forward who sold Belletti a dummy before slotting home. It was a dream start for Chelsea and, with their away goal scored at the Camp Nou, they were ahead in the tie.

Chelsea, though, seemingly not content with their slender lead, continued to take the game to Barcelona who looked stunned by the Londoner’s approach. Nine minutes later, things got even better for the home side as Valdés parried a Joe Cole strike into the path of Lampard who fired home to send Stamford Bridge into ecstasy.

Lampard was experiencing the season of his career and would go on to score 19 goals in all competitions, including the brace at Bolton which secured Chelsea their first title in 55 years. Signed from West Ham in 2001, the midfielder had been instrumental the previous season under Ranieri in Chelsea’s run to the semi-finals. It was Mourinho’s psychology, however, which helped transform the England midfielder into one of the world’s finest.

Recalling later in his autobiography, Lampard identified the moment in which he first saw Mourinho’s talent for getting the best out his players in those early years. As Lampard remembered it, Mourinho approached him in the shower: “‘You are the best player in the world,’ he said without blinking. I was slightly confused as well as completely naked. ‘You,’ he said more forcefully, ‘are the best player in the world’, but added I had to prove it by winning trophies. I knew that I wasn’t the best player in the world, but I also knew what he meant. He had elevated me to a new level. I felt a massive surge in confidence. I was walking on air for the rest of that day.”

Mourinho’s personality had not only brought the best out of his players but also the Chelsea fan base who adored their new coach. Stamford Bridge was as loud as it had been in years as Chelsea looked to have the match under control, but their situation would improve further still as they were to grasp the tie in a vice-like grip.

Read | Ronaldinho and the eternal journey to joy

The Barcelona defence was all at sea with Belletti, in particular, struggling to contain the threat on the right. Assistance from his midfielders was almost non-existent, and Puyol and Márquez struggled to cope with the breakneck speed in which Chelsea had approached the match. Just two minutes after Lampard’s goal, Cole, performing so effectively in the absence of the injured Robben, was again the architect as he sent Duff through on goal with a precise first-time pass. The space afforded to the Irishman was staggering as he coolly stroked the ball past Valdés with ease.

Three-nil down on the night and trailing 4-2 on aggregate, Barcelona required two goals if they were to progress on away goals. Ferreira gifted the Catalans a glimmer of hope when he inexplicably raised his hand in the box, leading to referee Pierluigi Collina awarding a penalty for Rijkaard’s side. Ronaldinho stepped up and sent the ball under Čech’s diving torso to narrow the deficit, and the Chelsea supporters, who had been so euphoric just moments earlier, were tense and nervous. The tie was on a knife-edge, and shortly before half time, Barcelona’s Brazilian superstar would swing the pendulum back towards the Catalans.

Chelsea were defending in numbers, and when Ronaldinho received the ball on the edge of the penalty box surrounded by six men, there was seemingly nowhere for him to go. The Brazilian, however, provided a demonstration of the vision that only he and a handful of players ever to play the game have possessed. Following a quick shimmy, he laced the ball goalwards with almost no backlift as the stunned Čech stood motionless, watching in a state of bewilderment at the ball flew past him into the net. It was a moment of dazzling imagination from a player who had become the talisman for the Catalan side.

Ronaldinho, along with Rijkaard and Laporta, was one of the characters who had helped catapult the club to new heights and was hugely influential in laying the foundations for the Pep Guardiola era. Only signed after Barcelona’s pursuit of David Beckham fell through, Ronaldinho followed in the footsteps of Rivaldo and Romário. From 2004 to 2006, Ronaldinho was the most exceptional player on the planet. Combining his supernatural talents with strong leadership qualities, he developed into a player of substance who would inspire Barcelona to become the most entertaining side in Europe.

With half-time approaching, it was Barcelona who were in the ascendency and Eto’o came agonisingly close to adding his name to the scoresheet with a blistering strike that flew narrowly over the bar. Chelsea had been rattled and were no doubt grateful for the half time whistle. The spectators had been treated to a heartstopping 45 minutes of football, and a place in the quarter-finals still lay in the balance. A Barcelona goal would surely be enough to see them progress while a fourth for Chelsea would put the Blues back in the driving seat.

Rijkaard looked to seize the initiative as Barcelona approached the second half as they finished the first, ravenous in their hunt for that crucial goal. Belletti forced Čech into a fingertip save with a strike from distance before Puyol should have made the tie safe with a header that he put too close to the goalkeeper. Chelsea caused problems too, and Lampard produced a trademark strike from distance to sting the palms of Valdés and shortly after saw another long-range effort sail narrowly wide. The match was end to end, and Eto’o wasted a golden opportunity as he flashed over the bar from six yards.

Chelsea, who were usually so tactically disciplined and watertight at the back, were uncharacteristically leaving themselves wide open and conceding far too many chances for comfort. Barcelona, meanwhile, failed to grasp the opportunities presented to them, and in the 75th minute were made to pay for their wastefulness.

Read | The rapid decline of the once-great poacher Mateja Kežman

Chelsea won a corner on the left and Duff whipped the ball in to find the head of a backtracking John Terry who masterfully glanced into the bottom corner. Pandemonium ensued at Stamford Bridge as their captain had conjured the latest twist in this thrilling match. Barcelona were furious with the goal, claiming that Valdés had been blocked off by Carvalho, but their protests were brushed aside by the experienced Collina and Chelsea led 5-4 on aggregate.

The final ten minutes saw every Chelsea player camped in their half to form an impenetrable barrier to keep the waves of Barcelona attacks at bay. A free-kick awarded on the edge of the Chelsea box would provide the Catalans one final opportunity to send Barcelona through, but Deco’s scuffed effort triggered ironic cheers from those in the Shed End. Collina blew the whistle for full-time soon after as Chelsea held on to be crowned victors and secure a place in the quarter-finals.

Mourinho wasted no time in joining in the celebrations with his players as he sprinted on to the pitch to savour a moment that was arguably just as satisfying for him as winning the trophy itself. This was an extra special victory for the Portuguese against his former employers following the tension and vitriol that had engulfed the tie.

While Mourinho was ecstatic at how the intense affair had ended up, those in Barcelona colours were, understandably, crushed by the result, and unsavoury incidents occurred off the pitch at the final whistle. The usually easy going Rijkaard struggled to control his emotions on this occasion as he took offence to the celebrations of André Villa-Boas, and stewards were called into action as a ruckus broke out that included Ronaldinho and Eto’o. The Cameroonian was accused of spitting at a steward after claiming he had been the subject of racial abuse, and mayhem subsequently erupted in the tunnel.

Eto’o recalled the incident, while also sharing his repulsion for Mourinho, saying: “Just look at the coach, he’s not respectable. This is the mentality of this football club.” Rijkaard, meanwhile, downplayed the incidents when interviewed later but made it clear that Chelsea’s ethics didn’t align with his: “It wasn’t a big deal,” he said. “Someone came forward and insulted us, our bench. I don’t know who. I don’t really want to say what I think about it. Normally you feel bitter after a loss, but maybe I feel a little bit more bitter because of the lies that were told before this game.”

Mourinho said he had seen nothing of the post-match trouble as he saluted his players: “I enjoyed much more the end of this game than other games,” he said. “I have played in finals, and I didn’t run like we did today. It was a reaction of a big team. I saw on the pitch players, coaches, the medical department.” He insisted there was nothing personal between him and Barcelona and added: “I want Barcelona to win the Spanish league.”

Mourinho’s admiration for Barcelona wouldn’t last long, however, as the two sides would meet again 12 months later at the same stage of the competition. By this point, the relationship between Mourinho and Barcelona had soured, and after Laporta appointed Guardiola over Mourinho in 2008, the respect between both parties had evaporated.

Rijkaard would continue as Barcelona coach until 2008, a period in which they conquered Europe while twice being crowned LaLiga champions. Ironically, the Dutch legend was once considered the favourite to take over when Abramovich fired Mourinho in 2007, only for the move to never materialise. The five years he spent in charge at the Camp Nou proved to be the highlight of a managerial career that also saw him take on roles with Galatasaray and the Saudi Arabia national team.

The arrivals of Laporta and Abramovich, the clash of personalities between Rijkaard and Mourinho, and the likes of Lampard and Ronaldinho performing at the peak of their powers had all aligned to lay the foundations for a new continental rivalry. Chelsea-Barcelona in 2005 was a classic, riveting affair and was the first episode in a series of epic clashes that would create chaos and controversy in the years that were to follow.

By Aaron Attwood @ajattwood