Pep Guardiola had been asked on Tuesday how he might stop Lionel Messi. The Manchester City manager simply laughed. There is no way to stop one of the allâ€‘time greats, as Guardiola himself knows better than most from his four years in charge at Barcelona, and the Argentina international reâ€‘emphasised the point to make this a difficult homecoming for his former manager.
Messiâ€™s hat-trick came courtesy of three sumptuous swipes of that left foot and the latest statistic to laud his genius shows that he now has 16 goals in 15 games against English clubs. In truth he has been punishing all-comers for as long as anybody can care to remember. This was the 37th hat-trick of Messiâ€™s career.
Guardiola felt this daunting assignment would offer a gauge of the progress of his City team and there were some positives for him to take. He was extremely adventurous with his tactics, which took in the headline decision to omit Sergio AgÃ¼ero from the starting XI, in an attempt to get an extra body in midfield and he watched his players work the Barcelona goalkeeper, Marc-AndrÃ© ter Stegen, on a number of occasions.
There were spells when City imposed themselves while the shots-on-target count was only eight to six in Barcelonaâ€™s favour. And yet Guardiola was damned by the final scoreline and there would be the inevitable questions about the wisdom of the decision to introduce AgÃ¼ero with only 11 minutes to go â€“ in other words, when the game was gone. Barcelona had lost two of their key defenders in Jordi Alba and Gerard PiquÃ© to injuries in the first half and it was tempting to wonder how AgÃ¼ero might have troubled what became a makeshift back-line.
In the end, though, City were undone by errors. There was Fernandinhoâ€™s slip that ushered in Messi for his first goal and the loose pass from Ilkay GÃ¼ndogan that found only Luis SuÃ¡rez, who laid on Messiâ€™s third. But the most horrible mistake was the 52nd minute one from Claudio Bravo, which led to the goalkeeperâ€™s red card. Up until that point City were in the game. After it they were taken apart.
Guardiolaâ€™s tactical nuances underscored the occasion. His starting formation could best be described as 4-1-4-1 but, when City had the ball, Pablo Zabaleta, the right-back, stepped up and inside into midfield, alongside Fernandinho. John Stones, the central defender, too, was encouraged to step up and so were the more advanced central midfielders, GÃ¼ndogan and David Silva.
It felt as though long spells were spent in an attempt to decode it all, and the ever-evolving formations served to ask questions of Luis Enrique. Then again the Barcelona manager had Messi and that is some comfort. Remember what Indiana Jones did when confronted by the bad guy who wielded his swords so dramatically? He just shot him. Here Messi shot Guardiola.
The opening goal owed everything to Fernandinhoâ€™s slip, because he was the favourite to get to the ball before Messi, after it had squirted loose following Stonesâ€™s challenge on AndrÃ©s Iniesta. Guardiolaâ€™s approach was utterly meticulous but he cannot be relied on to check whether his players are wearing the correct studs. Messiâ€™s finish was marked by class and composure.
Barcelona had chances in the first half to add to their lead. SuÃ¡rez found the side-netting with a shot; Ivan Rakitic headed over from Messiâ€™s free-kick and Bravo had to back-pedal, leap and tip over his own crossbar, after he had only half-saved a shot from SuÃ¡rez.
The tie turned sharply after the red card. Messi scored his second when he jinked and threaded a low shot into the corner from the edge of the area and the hat-trick followed GÃ¼ndoganâ€™s aberration and SuÃ¡rezâ€™s assist. Neymar added the fourth, after dancing and shooting inside the area, having earlier seen a penalty saved by Cityâ€™s substitute goalkeeper, Willy Caballero. It had been awarded after a burst from Messi â€“ who else? â€“ was crudely halted by the sliding Aleksandar Kolarov.
For City there were further flickers. Kevin De Bruyne and Kolarov extended Ter Stegen but by then it was too late. The Barcelona substitute JÃ©rÃ©my Mathieuâ€™s dismissal for a second yellow card on 73 minutes was a footnote. After the draw at Celtic in their previous Champions League tie City have it all to do.