An early Sergio Aguero goal gave the hosts the initial advantage, before Edin Dzeko, David Silva and David Pizarro all found the back of the visitors’ net in the second half.
City boss Roberto Mancini was happy with his team’s efforts in dispatching what could have been a difficult opponent.
“It was a good night but not easy – Porto are one of the top teams in Europe and played very well. I’m happy we’re going into the next stage,” the Italian coach told Sky Sports.
“We want to get to the final if possible but it will be difficult. With teams like United, Valencia and Schalke in, it’s like the Champions League.
“The early goal was important because Porto played very well, they’re a very strong team.
“Porto had lots of possession and it’s not easy to play against them.
“We had other chances to score, but when you don’t score you can have some problems.
“We played a good game. Maybe 4-0 was too much but it was important we went into the second stage. 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,” he concluded.
By Gareth McKnight
[ffcvideo file=”tfcbtitle3″ type=”mp4″ image_type=”jpg”]