Negredo, in particular, has been proved unstoppable this season and the Spain striker took his tally in five months in English football to 20 goals with a header that lit up an otherwise forgettable first half.
Jesus Navas set clear Fernandinho down the right and the Brazilian's cross to the back post was headed forcefully into the net by Negredo.
The second half was a different story as City cut loose.
Negredo scampered onto a curling, crossfield pass by substitute Aleksandar Kolarov to clip a finish high into the net in the 47th minute and Dzeko expertly turned in Navas' cut-back to make it 3-0 in the 67th.
Aguero, who has been out since Dec. 14, came on to a great reception and was soon celebrating a goal as he swiveled to shoot low into the net from Dzeko's pass.
Dzeko had the final say from another Navas cross in the 79th.
City scored four or more goals in a game for the 11th time this season. It has 64 goals in 16 home matches.
