Adam Johnson opened the scoring in the ninth minute and skipper Carlos Tevez doubled the Blues' advantage on the quarter-hour mark from the penalty spot.
Second-half strikes from David Silva, Patrick Vieira and Yaya Toure completed the rout as City leapfrogged Chelsea in the table.
Roberto Mancini's side are now six points ahead of Spurs, who have a game in hand.
Sunderland, meanwhile, have gone seven league games without a victory and need rapid improvement if they are to avoid being dragged into the relegation dogfight.
Source: PA
Source: PA