Manchester City powered into the last 16 of the Europa League at the expense of holders Porto, who had a man sent off late on last night.

Sergio Aguero set up victory by extending City's 2-1 first-leg lead after just 18 seconds before hitting the bar later in the first half.

Edin Dzeko came off the bench to add a second after 76 minutes before the sending off of Rolando preceded further goals from David Silva and David Pizarro in the closing minutes.

Although the decisive strikes came late, the result did not flatter the Barclays Premier League leaders.

The Portuguese champions may have controlled the game at times but they lacked a cutting edge and Roberto Mancini's side always looked more threatening in attack.

He said of the contest: "We played a good game. Maybe 4-0 was too much but it was important we went into the second stage.

"Porto had lots of possession and it's not easy to play against them."

The Italian was pleased to see Pizarro come on and score his first goal for the club.

Mancini continued: "I know him very well, he was with me at Inter. He came on for 20 minutes, played very well and scored a goal. His experience can be very important for us."

On their future prospects in the competition, Mancini added: "We want to get to the final.

"It will be difficult but for this reason I will play the best team, although we can make some changes every game."

Vincent Kompany, the Belgian defender, believes they can win the competition. The City captain said: "It was a great victory. I think we showed how serious we are about this competition. I didn't think we were at our best but we did what we needed to do."

Mancini also said he had "no problem" with Carlos Tevez, who apologised for his actions in taking an unauthorised three-month leave of absence from the club, and claimed the striker could be considered for selection in "two or three weeks".

"Carlos, has apologised to everyone and it's finished. I have no problemwith him but I think he needs two to three weeks to train, then some games," he added.