Salomon Kalou gave Chelsea reason to smile again as the Londoners closed in on Manchester United at the top of the table through a 2-0 victory over Manchester City.
After Richard Dunne opened the scoring for Chelsea with a sixth minute own goal, Kalou extended the lead in the second half to narrow the gap to two points at the top of the table.
United can still restore its five-point advantage when it faces Middlesbrough on Sunday but Chelsea gave a warning it is hot on the Red Devils' heels.
It was just the response coach Avram Grant was looking for after the disappointing Champions League quarter-final, first leg defeat by Fenerbahce in midweek.
With Arsenal having to settle for a draw against Liverpool, Chelsea was aiming to take advantage and got off to the perfect start by taking the lead after only six minutes.
Michael Essien raced forward for the visitors and slipped a pass to Nicolas Anelka on the right.
He swept it into the area and City skipper Richard Dunne got his bearings wrong, toe-poking his attempted clearance beyond goalkeeper Joe Hart.
City, though, kept its head and, by midway through the first half, was beginning to set the tempo carving out a number of chances in the space of a few minutes to rattle its high-flying opponent.
Benjani and Stephen Ireland linked up in the 28th minute only for the Republic of Ireland midfielder's effort to be blocked.
Then Petrov thumped in a fierce drive that was superbly tipped away by Cudicini at the post.
Chelsea again found itself on the back foot and Ashley Cole hacked the ball off the line in the 31st minute, the England defender showing good awareness after Johnson's effort had been deflected to leave Cudicini stranded.
Chelsea hit back and Kalou got clear only to send a shot wide of the post. It was a brief respite as Ireland sent a shot into the goalkeeper's body after 38 minutes.
Chelsea had lost some of their momentum and Grant made a change in the 51st minute, bringing on Joe Cole for Shaun Wright-Phillips.
They immediately looked more threatening and Kalou extended the lead two minutes later with a cool finish.
He latched onto a through ball from Essien and rounded Hart to find the corner for his 11th goal of the season .
Nicolas Anelka almost added a third in the 55th minute only for his header to come back off the bar following a cross from Frank Lampard.
City was forced to make a change in the 58th minute when Onuoha was stretchered off after suffering a shoulder injury in a fall.
He was replaced by Sun Jihai as they attempted to try to peg back Chelsea's lead.
The title chasers, however, were looking dangerous every time they broke forward.
Anelka got clear down the left in the 63rd minute and picked out Kalou but his effort was blocked by Gelson Fernandes.
Petrov almost pulled a goal back with a fine free-kick that was just off target.
Chelsea, though, never looked like giving up the two-goal advantage and got the result it wanted.
City, however, are in free fall and have now won only once in seven games.
English Premier League
Manchester City 0
Chelsea 2 (Dunne 6og, Kalou 54)