The hosts took the lead in the sixth minute when Sergio Aguero was given space to find the net from outside of the box.
City controlled much of the half after going ahead, and they could have gone 2-0 up but for Ben Foster's save from David Silva's effort.
Carlos Tevez had his first strike of the match 20 minutes in, but he could only flash his shot high and wide.
Micah Richards came close to doubling his side's lead when his shot was cleared off the line by Craig Dawson after Keith Andrews had seen his chance saved at the other end.
It didn't take long for Roberto Mancini's side to extend their advantage after the break as Aguero converted from Nasri's neat pass.
The game was put to bed soon after when Tevez found the net courtesy of a deflection off Nicky Shorey.
However, City weren't done there as Silva chipped the ball deftly over Foster to make it 4-0.