Manchester City left it extremely late before Samir Nasri arrived in the box to send Chelsea back to London with nothing to show for their hard work.
The home side had the best of the early spells with Nasri hitting the bar.
But, it was Chelsea who struck first, when City failed to clear the ball from a corner and Gary Cahill reacted first to the loose ball, which deflected in off Yaya Toure.
City did equalise through a Sergio Aguero penalty. And with only 5 minutes remaining on the clock, a delightful reverse pass by the substitute Carlos Tevez gave Samir Nasri the opportunity to chip Chelsea goalkeeper Petr Cech from 5 yards, which he dually obliged.
This was the first time Tevez had played for City since his controversial walkout in September of last year.
The victory allows the Manchester giants to continue their 100% winning run at the Etihad Stadium. A 20 match run of victories that doesn't look like ending anytime soon.
The win keeps the blue half of Manchester hot on the heels of rivals United, and also gives Chelsea's Roberto De Matteo his first defeat as manager since taking over from Andre Villa-Boas.