Chelsea struck a huge blow in the title race with a highly energetic, composed performance in beating Manchester City 1-0 at the Etihad Stadium on Monday night.
Branislav Ivanovic's crisply struck shot in the first half proved to be the difference between the two sides on the scoresheet, but Chelsea ultimately deserved the victory due to being vastly superior to their opponents all over the pitch, as City's run of 11 straight Premier League victories at home was brought to a shuddering halt.
Samuel Eto'o, Nemanja Matic and Gary Cahill all hit the woodwork as Chelsea shocked many by attacking with far more intensity than had been imagined, with Eden Hazard and Willian both starring and breaking forward at will.
City were left to rue a disappointing night, one that they'll be keen to move on from as soon as possible.
Here are six lessons learned from the heavyweight clash.