Trailing 2-0 from the first leg, City's best early chance was a Samir Nasri shot that was saved by Victor Valdes.Lionel Messi finished a Cesc Fabregas pass midway through the second half and Pablo Zabaleta was later sent off.Vincent Kompany prodded in from Edin Dzeko's flick but Alves turned in from Andres Iniesta's cross in added time.City's first foray into the knock-out stages of this competition might have ended at the first hurdle, but the Premier League side played with far more conviction than in the first leg at Etihad Stadium.Having won the Capital One Cup and lost in the FA Cup quarter-finals to Wigan at the weekend, Manuel Pellegrini's side now have only the Premier League - where they are nine points behind leaders Chelsea but have three games in hand - to concern them.They will wait anxiously for news on the injury that forced Sergio Aguero, who has already missed two chunks of the season, off at half-time.The visitors were angered by French referee Stephan Lannoy's decision to ignore what looked to be a Gerard Pique foul on Dzeko, leading to Zabaleta being shown a second yellow card for his protests with 12 minutes remaining.But City, who impressed with their willingness to press high in the early stages without ever hurting Barcelona, had been fortunate themselves when Joleon Lescott caught Messi in the area after seven minutes.They were also lucky when Neymar touched in from a Jordi Alba cross, only for Alba to be incorrectly called offside.Barcelona, who are now through to the last eight, posed a persistent threat and when the outstanding Messi burst forward and threaded a pass through for Neymar midway through the opening 45 minutes, Joe Hart did well to turn around the post before the goalkeeper later denied Xavi.The visitors' best opening of the first half came when Yaya Toure lifted a ball into the area and David Silva guided a flick back to Nasri, only for the Frenchman to shoot straight at Valdes.Just before the break Messi carved City open again, resulting in Neymar's shot being headed off the line by Fernandinho.After the restart Lescott gave possession away on halfway and Messi beat the centre-back before seeing his stab at goal come back off the post.Aguero's replacement Dzeko was giving City more thrust in attack and the Bosnian's firm header from Kolarov's fine cross from the left was pushed away from the top corner by Valdes.Shortly afterwards City wasted an excellent opening after Barcelona's defence failed to deal with another Kolarov cross but Zabaleta sliced his first-time shot well wide.Barcelona ended any lingering doubts when Lescott failed to deal with a Fabregas pass and Messi guided a shot into the corner.And Hart then had to make a scrambling save to turn wide from Xavi as Barcelona went close to a second.City felt they should have had a spot-kick from Pique's challenge on Dzeko - and seconds later they were further frustrated when Zabaleta saw red while protesting against the decision.Even with 10 only men, they managed to pull one back when Kompany finished from Dzeko's flick with a minute left.But in added time, Barcelona exploited the space left by City at the back and Alves, who also scored late on at Etihad Stadium, squeezed a shot over the line from Iniesta's pass.(BBC)ANN.Az