Champions League: Barca beats Man City, Juve edges Dortmund

Manchester City's Sergio Aguero celebrates after scoring during their Champions League round of 16 first leg soccer match against Barcelona in Etihad Stadium in Manchester, Feb 22, 2015. [Photo/Agencies]

Sergio Aguero rewarded City for a vastly improved second half showing with a clinical strike 20 minutes from time.

But with City down to 10 men after Gael Clichy's red card for a second booking, the majestic Messi had the chance to restore Barcelona's two-goal lead but his penalty was saved by Joe Hart and the Argentine headed the rebound wide.

"We are very happy with the result and even if it was 3-1 the tie would still be open," Barca coach Luis Enrique said. City midfielder Samir Nasri said in the build-up that while Messi played football from a different galaxy, the rest of Barca's squad shared the same planet as City's.

It did not look like it in a horribly one-sided first half in which Barcelona's entire ensemble were light years ahead in speed and movement.