Manchester: The presence of former manager Andre Villas-Boas at Eastlands failed to inspire holders Porto as Manchester City eased into the last 16 of the Europa League with a 4-0 second leg win on Wednesday.

Goals from Sergio Aguero, Edin Dzeko, David Silva and David Pizarro -- the last three in the space of nine minutes late in the second leg tie -- ensured a comfortable evening for City, who won 6-1 on aggregate.

The goal rush came against a Porto side who played the final 14 minutes with 10 men after the sending off of defender Rolando for a second yellow card.

"We played a good game," City manager Roberto Mancini told ESPN.

"Maybe 4-0 was too much but it was important we went into the second stage," added the Italian, looking to become the first City boss in 42 years to bring a major European trophy to the club.

Premier League leaders City took just 19 seconds to extend their first leg advantage when Aguero grabbed the quickest goal in the Europa League this season.

Argentinian defender Nicolas Otamendi lost the ball around the halfway line, and Nigel de Jong found Yaya Toure whose pass sent Aguero racing clear of the Porto backline.

He took his chance brilliantly with a clinical finish into the bottom left-hand corner.

Porto responded gamely as Joao Moutinho volleyed wide, Silvestre Varela headed at Joe Hart and defender Maicon ended a marauding right-wing run with a wayward centre across goal.

But for all Porto's possession, City looked far more dangerous and Silva's well-weighted through ball after 16 minutes sent through Yaya Toure whose progress was well-blocked on the edge of the area by goalkeeper Helton.

City again came close with Silva's through ball forcing Helton to race from his area to try to intercept Aguero. The City forward skillfully rounded the goalkeeper but his shot from the edge of the area struck the Porto crossbar.

Mancini's team, were content to withstand the modest pressure from Porto and play on the counter-attack, with Aguero involved in a pacy break before the interval which ended with a pass to Yaya Toure.

Despite terrible initial control, the City midfielder eventually managed to re-connect with Aguero only for the goalscorer to flash a poor shot wide.

Hulk saw a fierce free-kick deflected behind and Rolando volleyed over from six yards at the resulting corner as every passing minute left Porto facing a bigger obstacle.

After the restart, Lucho Gonzalez poked wide from 18 yards, Hulk's low cross-shot was spilled by the diving Hart who was relieved to see the ball travel to safety and James Rodriguez had the ball in the net after 57 minutes only for his 'goal' to be ruled out for offside.

City weathered that brief storm, however, and their second goal, in the 76th minute, put the outcome of the tie beyond all doubt.

Aguero was the creator, holding the ball intelligently outside the Porto area and waiting for the overlapping run of substitute Dzeko who took the ball in his stride and finished expertly from 10 yards.

Porto's hopes of an unlikely recovery were hampered by the dismissal of Rolando who collected a second yellow card prior to the re-start for dissent.

Silva added to what had become a rout six minutes from time when he turned the ball into an open goal after substitute Pizarro burst into the area and crossed selflessly from the right.

Pizarro himself completed it, in the 86th minute, starting a move outside the area and collecting a poor touch-on from Dzeko before slotting past the helpless Helton.

Hart ensured Porto did not even leave Manchester with a consolation goal, diving low to the foot of his post to keep out a shot from Hulk.