In trying to explain exactly how Barcelona achieved the exceptional on Wednesday night, Luis Enrique could only really reach for intangibles.

“The key was the faith in the team and the fans right until the 95th minute,” the Barca manager said. “It was a victory of faith.”

Or, to use different words for the same idea, a victory of belief… of mentality. In fact, it’s difficult to think of a match so significantly conditioned and influenced by fundamental psychology. This could have been a research case study, as much as one of the most riveting games in European history.

Barcelona vs PSG player ratings Show all 22 1 /22 Barcelona vs PSG player ratings Barcelona vs PSG player ratings Marc-Andre ter Stegen - 6 out of 10 Was rarely tested on an evening when all the action was taking further place up the pitch. Did his job when called upon. Getty Barcelona vs PSG player ratings Gerard Piqué - 7 Defiant and resilient throughout, displaying composure at the back and technical ability on the ball too. Getty Images Barcelona vs PSG player ratings Javier Mascherano - 7 Gave his all. Showed his intent from the start, putting in a series of important challenges and blocks. AFP/Getty Images Barcelona vs PSG player ratings Samuel Umtiti - 7 Dominant in the air and dominated in his battles with Cavani. Getty Images Barcelona vs PSG player ratings Rafinha - 6 Dangerous in drifting in from the flank and excellent in finding the right space but some of his deliveries were off the mark. Nonetheless, proved to be a nuisance for much of the night. Getty Barcelona vs PSG player ratings Sergio Busquets - 6 It was a scrappy and frantic night for the Spaniard. His challenges were mistimed and his passes misjudged but his energy was still invaluable in Barcelona's pressing game. Getty Images Barcelona vs PSG player ratings Ivan Rakitic - 7 A bundle of enegery throughout. His challenges were vital in breaking up PSG's forward game but almost cost Barcelona the game in allowing Kurzawa to set up Cavani for his away goal. Getty Images Barcelona vs PSG player ratings Andres Iniesta - 7 Pulled the strings for much of the, playing passes left, right and centre, and wasn't afriad to try his luck from outside the box. Dwindled in influence as the game wore on. AFP/Getty Images Barcelona vs PSG player ratings Lionel Messi - 7 Here, there, everywhere. It was another trademark performance from the Argentine but on this occasion he wasn't the man who Barcelona turned to. AFP/Getty Images Barcelona vs PSG player ratings Luis Suárez - 7 Showcased the best of his poaching abilities to snatch Barcelona's first goal and proved to be a menace for the entire 95 minutes. AFP/Getty Images Barcelona vs PSG player ratings Neymar - 9 Absolutely sensational. Was instrinsic to Barcelona's late fightback, scoring their first fourth and fifth goal before setting up Sergi Roberto's winner with an exquisite assist. Getty Barcelona vs PSG player ratings Kevin Trapp - 5 Poor decision-making handed Barca their first and failed to effectively deal with Iniesta's back-pass for the second. AFP/Getty Images Barcelona vs PSG player ratings Thomas Meunier - 4 His ill-timed foul on Neymar handed Barca their first penalty and third goal. Let down by sloppy mistakes. AFP/Getty Images Barcelona vs PSG player ratings Marquinhos - 4 Should have done much better for Barcelona's second, failing to assert himself against Iniesta inside his own box. It was night to forget in all for him. AFP/Getty Images Barcelona vs PSG player ratings Thiago Silva - 6 As ever, Silva was PSG's warrior. But although he rarely shirked a challenge even he was suspectible to lapses in concentration tonight and poor decision-making. Getty Images Barcelona vs PSG player ratings Layvin Kurzawa - 4 His disastrous attempt at a goal-line clearance handed Barcelona their second and he clearly struggled against Rafinha's pace and trickery. Impressive assist for Cavani's goal but, in all, the occasion appeared to get to him. AFP/Getty Images Barcelona vs PSG player ratings Adrien Rabiot - 5 Failed to deal with Barcelona's high-intense approach and incessant press. AFP/Getty Images Barcelona vs PSG player ratings Marco Verratti - 6 Started well but grew increasingly timid and quiet as the game wore on. Conceded a number of unnecessary challenges. AFP/Getty Images Barcelona vs PSG player ratings Blaise Matuidi - 4 Little of note to say. Looked overwhelmed at times. Getty Images Barcelona vs PSG player ratings Lucas Moura - 5 Kept himself busy in the first half but was repeatedly targeted by Barcelona's enforcers and struggled to shine as a result. AFP/Getty Images Barcelona vs PSG player ratings Edinson Cavani - 6 Did what was asked of him in expertly clinching PSG's vital away goal. Should have converted an early second-half chance though. Let down by his team-mates. Getty Images Barcelona vs PSG player ratings Julian Draxler - 5 Another player who failed to live up to the big occasion. AFP/Getty Images

The Nou Camp may have been the stage for it, but this was a match played in the mind, to a greater degree than almost any other. There were so many massive juncture moments that caused a complete shift in how both individual players and the entire teams were applying themselves, how they were reacting, and that thereby seemed to reveal what they were thinking.

Arsene Wenger was one of many watching on and engaged by that psychodrama as much as the drama of the unique challenge of whether Barcelona could pull off the greatest comeback in football history.

“I stayed there [watching it] because it is interesting on a psychological front to see how they respond, I wanted to see how Barcelona finished the game and in fact they had half given up,” Wenger said. “I looked more at it from a tactical point of view, what is going on mentally in the head of the players.”

This was one of those games where merely relaying the chronology of it in that sense is compelling because it’s not just about what is done with the ball, but why and how they’re doing it. It fully displayed how utterly crucial psychology is, and as important as tactics or talent or luck given how they all come together.

Luis Suarez's opening goal put the pattern in place for the subsequent 50 minutes (Getty)

The tone was set even before the game. When Luis Enrique insisted his side could score six, it would usually have been easy to dismiss it as the empty hopefulness that characterises those press conferences, except it was said with genuine conviction. He believed, and evidently made Barca believe. He began to convince you it was possible.

Barcelona played with that conviction. What’s more, the fulsome way that they immediately went at Paris Saint-Germain - with, you might say, a “lucid rage” - seemed to have an inverse affect on the French champions. Already so conscious of just defending their lead, and arguably to the point it was already having a corrosive effect on any assurance they possessed, Unai Emery’s side simply became more insecure and fragile. They weren’t lucidly raging. They were ludicrously panicking.

The Nou Camp will have known few atmospheres as tense as that on Wednesday night (Getty)

The goal after two minutes summed this up. While Luis Suarez was all determined focus, PSG - and especially goalkeeper Kevin Trapp - were all uncertain hesitation. The pattern of the next 50 minutes was put in place, as Barca had the tangible of a goal to bolster their intangible belief.

Luis Enrique’s side weren’t actually technically excellent at this stage, but they were doing everything with that extreme level of concentration. PSG were meanwhile withdrawing further and further, which actually created more and more uncertainty because of what it meant to be so defensive. It got to the point that a moderate display of Andres Iniesta’s velvet talent was actually able to confuse two of Emery’s defenders into farcically swiping the ball into their own net, before Thomas Meunier was resorted to trying to stop Neymar with his head while lying on the ground.

The story of Barcelona's incredible comeback against PSG Show all 13 1 /13 The story of Barcelona's incredible comeback against PSG The story of Barcelona's incredible comeback against PSG Barcelona's night got off to the best possible start with Luis Suarez scoring in the 3rd minute. Getty The story of Barcelona's incredible comeback against PSG Excellent improvisation from Andres Iniesta caused Layvin Kurzawa to convert the ball into his own net. Getty The story of Barcelona's incredible comeback against PSG After the half-time interval, Lionel Messi put his name on the scoresheet from the penalty spot. Getty The story of Barcelona's incredible comeback against PSG However, when Edinson Cavani grabbed a vital away goal for the visitors, Barca's hopes looked lost. Getty The story of Barcelona's incredible comeback against PSG Cavani could not hide his emotion after scoring the goal which, at that point, had looked to have ended Barcelona's hopes of qualifying. Getty The story of Barcelona's incredible comeback against PSG Three minutes from time, Neymar struck back with a splendid free-kick which beat Kevin Trapp at his near post. Getty The story of Barcelona's incredible comeback against PSG Into stoppage time, and after Marquinhos' foul, Neymar converted Barcelona's second penalty of the night. Getty The story of Barcelona's incredible comeback against PSG In the final minute of added on time, Neymar's lofted pass found Sergi Roberto in the box. Getty The story of Barcelona's incredible comeback against PSG The 25-year-old lifted the ball over Trapp and into the far corner to complete the Champions League's greatest-ever comeback. Getty The story of Barcelona's incredible comeback against PSG Sergi Roberto was duly mobbed by his teammates, as scenes of pandemonium spread around the Nou Camp. Getty The story of Barcelona's incredible comeback against PSG Unai Emery, meanwhile, could not look. Getty The story of Barcelona's incredible comeback against PSG As our chief football writer Miguel Delaney wrote, the night was one of the sublime, the ridiculous, and the historic. Getty The story of Barcelona's incredible comeback against PSG Barcelona progress into the quarter-finals, along with Bayern Munich, Real Madrid and Borussia Dortmund. Getty

At 3-0 up, Barca at that stage looked on the brink of something brilliant - but a mental threshold had actually already been crossed. It was if, because the prospect of this comeback was now very real rather than something to worry about, PSG were sparked into action. They decided to come at Barca, to try and expose that defence susceptible to the counter in the way they should have been when they had a healthier lead, and had their best spell of the game. Now so close to this much talked-of miracle, it was as if Barca got a bit complacent. They suddenly weren’t quite firing in the same way.

Soon, they weren’t firing at all. Edinson Cavani scored the goal that really should have killed the tie. That should have been it, and it did look like that was it.



It is the great irony to a great game packed with so many incidents and almost too many major events to keep track of. It was actually quite a dead, lifeless match for about 25 minutes, bar the two chances for Cavani and Angel Di Maria.

You could say those two “bottled it” but the thing at that point was that it didn’t seem to mean much, and they certainly didn’t bottle it in the way that was to come. It wasn’t even like Barca were particularly energised by those misses. Marc-Andre ter Stegen’s stop from Cavani was only crucial in prolonged retrospect. PSG were so comfortable that their players were back concentrating in the way they should have been with the immensely healthy lead of 4-0, as Marquinhos was now clearing efforts of his own goalline rather than directing them into the net.

Barca were still pushing… but not pushing in the way they had been.

Then Neymar got the defibrillator out, and generally gave his side some electronic shock treatment with that triumphantly good free-kick. There was a game again. There was also controversy again.

Luis Suarez undeniably looked to win the penalty, but this was almost a further example of the difference in mentality. Barca were fully immersed, and looking to push everything to the limit, whereas PSG could only retreat to the point that a cave-in became inevitable.

PSG's goalkeeper Kevin Trapp could not hide his disappointment at the final whistle (Getty)

That was so stunningly displayed by that remarkable stat that they only completed four passes after Neymar’s free-kick, and three of those were from tip after Barcelona had scored. By contrast, in the words of the key scorer Sergi Roberto, the Catalans were "throwing everything into it".