Chelsea did have an early scare when Ireland almost got on the end of Elano's delightful chip, which Petr Cech had to push past his left post.
Later in the half Petrov forced the Blues keeper to palm away a long-range free-kick, and Ireland should have done better when given time to pick his shot.
Other than that it was pretty much one-way traffic.
Essien gave the home side a deserved lead when Lampard slipped him in and it was no surprise when the England midfielder produced another quite sublime pass with the outside of his boot to send Drogba racing past Micah Richards for his third goal in as many games.
Chelsea were rampant and should have had a penalty moments later when Dietmar Hamann hacked down Drogba, while Joe Hart saved well from Kalou, who then appeared to be tripped by Richard Dunne in the box.
It proved academic, however, with the game over as a contest thanks to two further Chelsea strikes within 15 minutes of the restart.
Drogba hammered in his second after Lampard's shot had been brilliantly kept out by Hart and he squandered a fine opportunity to complete his hat-trick when Lampard unleashed another drive which Hart palmed away.
The powerful striker made amends with a cushioned header that sent Cole surging clear to finish with aplomb and pile on the misery for City boss Sven-Goran Eriksson.
With the visitors now concentrating on damage limitation, Chelsea could afford to bring on the out-of-sorts Shevchenko.
Chances continued to come their way and Essien carved open the shell-shocked City defence twice more to serve up opportunities which Kalou and Shevchenko gleefully accepted.
Chelsea boss Avram Grant:
"In the last month we have improved in every match. The players want to be better and have shown full commitment to positive football and winning - there are no big secrets behind this.
"We will enjoy this but we are in the middle of the process and want to continue it. I don''t think we will win many games 6-0. Manchester City are not an easy team to beat but we made it easier.
"We moved like we needed to and played our football. The fans know now we are trying to play positive football."
Man City boss Sven-Goran Eriksson:
"We forgot how to defend. If you give a team like Chelsea space and time that will happen. It was very bad defending from our side - we have to be much better than that.
"It has been a good story so far this season but I'm sorry for the fans who travelled here. There were a lot of them here, they wanted to see us play good football - not see us lose like we did.
"People are talking about us playing good football but you have to defend and be very aggressive. If you don't do that against a team like Chelsea this happens."
Chelsea:
Cech, Belletti, Carvalho, Alex, Ferreira, Joe Cole (Shevchenko 67), Essien, Lampard, Obi, Kalou, Drogba (Pizarro 80).
Subs Not Used: Cudicini, Makelele, Ben-Haim.
Booked:
Essien, Lampard.
Goals:
Essien 16, Drogba 31, 56, Joe Cole 60, Kalou 75, Shevchenko 90.
Man City:
Hart, Corluka, Dunne, Richards, Garrido, Ireland (Vassell 63), Hamann (Ball 66), Johnson, Petrov, Elano (Bianchi 73), Samaras.
Subs Not Used: Isaksson, Onuoha.
Booked:
Richards, Johnson.
Att:
41,832
Ref:
Mike Riley (Yorkshire).
