Messi came back to haunt his former manager with three very well taken goals and the result will be a big wake-up call for City, who still have a long way to go to reach Barcelona's level.
Manchester City matched Barcelona in the opening stages of the game, with neither team having any real chances. However, you can only keep Lionel Messi quiet for so long and in the 17th minute, the Argentinian opened the scoring.
Messi passed to Iniesta, who attempted to play a pass back to the forward. Fernandinho seemed to have cut out the pass but slipped at a crucial moment, leaving Messi with the simplest of chances. The Barca star rounded Bravo and placed his shot into an empty net.
At 1-0, it looked like City maybe could have got themselves back into the game. Ter Stegen made an excellent save to prevent Gundogan from scoring and Stones headed just wide in the first 45 minutes.
The match went from extremely difficult to near impossible for City, who had goalkeeper Claudio Bravo comically sent off on his return to his former club. The goalkeeper came out of his area, attempted a pass but played the ball straight to Luis Suarez. The Uruguayan tried to chip the Chilean 'keeper who stopped the effort with his hands, receiving a red card.
Soon after Bravo's sending off, Messi made it 2-0. The forward received a pass from Iniesta just outside the area, cut inside from the right and placed his shot perfectly past substitute goalkeeper Willy Caballero.
Another individual mistake played a huge part in Messi and Barcelona's third goal after Gundogan's pass to Stones was misplaced straight into the path of Suarez who squared for Messi and the forward made no mistake with a simple finish.
The second red card of the evening was awarded when Jeremy Mathieu cynically brought down Raheem Sterling for the second time in the second half, receiving his booking of the game.
Barcelona had the perfect chance to make it 4-0 when they received a penalty following Kolarov's foul on Messi. Neymar stepped up to take the spot kick, but the Brazilian produced a weak effort that was easily saved by Caballero.
However, the Barcelona forward didn't have to wait much longer for his goal, when just moments later he fired past Caballero in the dying stages of the game.
It was an impressive performance from Barcelona who dealt with a strong Manchester City side very well. The only negatives for Luis Enrique would be injuries to Jordi Alba and Gerard Pique.
As for Pep Guardiola's side, they weren't as bad as the scoreline suggests and it would have been a much more interesting contest in the second half had Bravo stayed on the field. Even so, they still have a long way to go to become one of Europe's best.