A torrid day for City down in London, as they were put to the sword by a rampant Chelsea side.
Jimmy Floyd Hasselbaink and John Terry opened the scoring before half-time.
Before Mario Stanic, Frank Lampard and William Gallas all got in on the act to complete the rout in the second half.
Chelsea's largest-ever win over City at the Bridge, the champions dug their teeth in against a third-placed City.
Didier Drogba bagged a brace, alongside goals from Michael Essien, Joe Cole, Salomon Kalou and Andriy Shevchenko.
City had come into the game five unbeaten in the league, but were truly torn apart at the Bridge.
Man City, admittedly fielding a much-weakened side, stood no chance in West London, as Chelsea marched on through to the fifth round of the FA Cup.
Goals from Diego Costa, Willian, Gary Cahill, Eden hazard and Bertrand Traore ensure the Blues progressed, with Frenchman David Faupala scoring a consolation for City.
With just six regulars in the starting XI for City, they were left without hope and fell on the wrong side of another drubbing at the Bridge.