As many predicted would happen on Tuesday night, Barcelona delivered a masterful performance at the Etihad Stadium and took full control of their Champions League Round of 16 tie against Premier League champions Manchester City. In the first half the quality of Barça’s football took the breath away and two goals from Luis Suárez put them in a commanding position. But for the heroics of Man City goalkeeper Joe Hart, the second leg would be a mere formality. As it is, the tie is still just about alive thanks to a second-half goal from Sergio Agüero.

It was a game of three phases: the first half; the second half before the red card; and the second half after the red card. Barça had by far the better of the first half, City comfortably dominated the second half until Gaël Clichy’s brainless dismissal, and Barça passed their way to the final whistle in the final stage.

Throughout the game Man City looked uncomfortable playing in a deep 4-4-2 and, particularly in the first half, they never got anywhere near Barça, whose confidence grew as the half progressed. Lionel Messi was at his mesmeric best, popping up all over the pitch and picking City apart at will. Sergio Busquets was left free to run the game and he did exactly that.

By the time the whistle went for half-time, Barça could have been three or four goals to the good and City’s players were completely demoralised. They knew they had been outclassed and some had even stopped running when Barça had the ball. By contrast, Barça’s press repeatedly prevented City from playing a useful first pass out from the back. It was common to see moments like the one in the screengrab below, in which a City defender had the ball under pressure and with no passing options available.

In the second half, Barça made the fatal mistake of easing up and City got themselves back into the game. As the visitors’ tempo dropped with and without the ball, the hosts’ rose and David Silva’s superb movement and vision prised Barça open repeatedly. The Spaniard created Agüero’s goal with a smart horizontal run and deft lay-off and Luis Enrique was spooked into reconfiguring his midfield to create a more dynamic barrier in front of the defence. Messi’s missed penalty in stoppage time means City head to Camp Nou with an outside chance of getting a result, but on this evidence Barça should progress comfortably.

There were no surprises in Luis Enrique’s starting eleven. Marc-André ter Stegen replaced Claudio Bravo in goal, as is customary in cup games, while the back four of Dani Alves, Gerard Piqué, Javier Mascherano and Jordi Alba was a more familiar unit than those we have seen in the league of late. Sergio Busquets, Ivan Rakitić and Andrés Iniesta played in midfield and Lionel Messi, Luis Suárez and Neymar started up front.

Man City played a more defensive version of their regular 4-4-2 system. They were missing the titanic Yaya Touré in midfield and while common sense dictated that Manuel Pellegrini would surely select Fernando and Fernandinho to anchor in Touré’s absence, it was actually James Milner who partnered Fernando, suggesting that City would attempt to fight fire with fire. What actually happened was that all steel was removed from the City midfield – they were simply unable to halt Barça’s advances in the first half.

It was also surprising to see Martín Demichelis picked ahead of Eliaquim Mangala in the centre of defence and Edin Džeko starting alongside Sergio Agüero in attack. Mangala was bought to play in exactly this type of game and yet the ageing centre-back who cost City the match against Barça last year was preferred. As it happened, Demichelis gave a creditable display – much better than that of his defensive partner Vincent Kompany.

Pairing Džeko and Agüero meant that City played their 4-4-2 with two out-and-out strikers – an adventurous move from Pellegrini but one that ultimately backfired. Just a few days after Javi Gracia’s Málaga showed how to beat Luis Enrique’s Barça, the Chilean chose not to surrender the ball and pack the midfield and tried to attack as normal. Coaches of English teams repeatedly make this hubristic tactical choice against Barça and they almost always pay the penalty.

The first few minutes saw Barça control the tempo of the game by keeping the ball and circulating it in deep areas. On a couple of occasions they could have broke forward but their conservative positional play meant there was no-one ahead of the ball when promising situations developed. It was fine, though – the plan was clearly to starve City of possession and then to step up a gear once domination was established.

This was exactly what happened. After ten minutes or so Barça’s players had figured out where City were leaving spaces (everywhere), where the most reliable passing lanes were and how and when to use them. they set about winning the game. Busquets, Rakitić and Iniesta moved the ball quickly and accurately, but there was no denying that Messi was the star of the show, seeing a lot of the ball in deep areas and surging forward through City’s wide open midfield into acres of space in front of the defence.

One of the best things about Messi playing at his best is the multiplier effect he has on his teammates’ abilities: as soon as he got into top gear, the entire team was infused with confidence and suddenly everything about football was almost as easy for them as it is for Messi. Jordi Alba surged forward at will, Iniesta pinged first-time passes as though it was 2010 and Piqué had perhaps his best half of the season. City had no answer.

Suárez opened the scoring on sixteen minutes after an error from Kompany set him up for a free shot from six yards, and the Uruguayan slid in to double his tally just before the half-hour mark, after yet another Messi slalom through the centre freed Alba to square low into the corridor of uncertainty under no pressure whatsoever. It was no less than Barça deserved – if the first goal was slightly fortunate, the second was a perfect depiction of the gulf in class between the two sides.

The second half was an altogether different beast. Barça’s intensity levels dropped markedly, Busquets’ majestic performance turned into an arrogant one and City’s direct attacking moves were suddenly more focused and incisive. Dani Alves was left exposed by Messi’s roaming and in this form it doesn’t take much for opponents to have success when attacking him.

City attacked at will and produced five shots between minutes 46 and 60 to Barça’s one. An error from Alves gave Agüero a clear opening, but Mascherano appeared from nowhere to block the goalbound shot. An even better opportunity fell to Džeko, who was left totally free by Busquets and Piqué to head at goal from six yards following a left-wing cross. Fortunately, the big Bosnian planted his header straight into ter Stegen’s hands.

The tone was set for the game’s second phase, though, and City were the dominant side. Pellegrini sensed the change in momentum and sought to keep his side in the ascendency with a couple of substitutions. First, he brought Fernandinho on for the disappointing Samir Nasri, giving City a more solid foundation in midfield and moving Milner out to the right to match Alba’s energy levels on that flank. Then he replaced Džeko, who had taken a game-leading six shots but hit the target with only one, with Wilfried Bony, who was expected to improve on that conversion rate.

Within a minute of Bony’s introduction City had scored. Messi gave the ball away to Clichy, who squared for Fernandinho. Busquets was slow to close him down, which meant that Fernandinho had lots of time to pick a pass into the huge amount of space between Barça’s centre-backs and also between defensive line and their midfield. Inevitably, David Silva had spotted this space and, in one movement, ran into it, dragged Barça’s central defenders out of position and laid off for Agüero, who finished expertly.

Luis Enrique responded to Barça’s sudden porousness by bringing on Mathieu in place of Rakitić, who was unfortunate to be removed, and moving Mascherano into the pivote position. Perhaps the more logical switch would have been to take Busquets off, as he simply isn’t as effective as an interior midfielder, but his defensive qualities were needed on that side and his still undervalued understanding with Messi is always extremely useful.

Just when it looked like City were in a position to mount a comeback, Clichy got himself a second yellow card with a stupid challenge on Alves and pretty much killed his side’s chances of getting a result. Adriano replaced the injured Alves – Luis Enrique must have been very glad to have a reason to take the full-back off besides his below-par performance – and Barça re-asserted themselves, opening up the field with wide positioning and passing City to death.

The stats show just how much Clichy’s red card changed the game. Between minutes 46 and 74, at which point Clichy was dismissed, the possession figures stood at City 39.2% and Barça 60.8%. During this period City out-shot Barça seven to three and had six corners to Barça’s one. Between minutes 74 and 90, after the red card, Barça’s share of the ball jumped to 73.8%. They out-shot City four to zero, had two corners to City’s none and won and missed a penalty.

As one would expect, once Barça had an extra man Iniesta came to the fore. He may lack the dynamism to fit perfectly into Barça’s new style of play, but when his brief is simply to pass and move, maintaining possession and advancing incrementally up the pitch, he’s still an unbelievable player. No player had more than the captain’s 113 touches and his intelligent link-up with Messi and Alba was key to Barça’s excellent showing.

On eighty minutes, Pedro replaced Neymar, who had taken a more supporting, fixed role in the side to balance out Messi’s free-roaming heroics. Neymar took just one shot, while Messi had four and Suárez five, and had 49 touches to Messi’s 106. That isn’t to say Neymar played badly – he did his job – but if there was one City player besides Hart who deserved credit it was Pablo Zabaleta, who made more tackles and interceptions than anyone else on the pitch.

Zabaleta had also cleared off the line and made a goal-saving tackle, but his good work appeared to have been undone in stoppage time when Messi and Pedro played a one-two to send Messi through on goal and the Argentine right-back’s clumsy lunge conceded a penalty. Messi’s effort was frankly abysmal and Hart’s save means that Messi has now missed five of his last ten spot-kicks for club and country.

The vast majority of Barça fans would have taken a 2-1 win before the game, but having witnessed a first-half of such awesome quality as well as a sixteen-minute period in which Barça had a man advantage, it feels a bit like Barça underachieved at the Etihad. Still, they remain clear favourites to progress to the quarter-finals and if they produce more displays like this, they could go all the way.