Lampard's first-half strike made it five successive league wins for Chelsea, but the result leaves Pearce needing a positive result at Middlesbrough on Saturday to banish the storm clouds surrounding his future as City manager.

While the focus lay firmly on City and newly-appointed England Under-21 manager Pearce following his team's abject FA Cup quarter-final defeat at Blackburn at the weekend, a loss which left his position under threat, this game also carried huge significance for Chelsea.

With Premiership leaders Manchester United nine points clear at the top of the table, anything other than three points for Mourinho's team would have handed Sir Alex Ferguson's men a major psychological lift ahead of the title run-in.

The home side, subjected to chants of 'You're not fit to wear the shirt' by their own supporters as they slid to defeat at Blackburn, were hugely motivated, however, and they made life tough for Chelsea in the early stages.

And although Pearce's team failed to worry goalkeeper Petr Cech with any serious efforts on goal, the commitment of midfielders Joey Barton and Sun Jihai kept Chelsea subdued prior to Lampard's penalty opener.

City defender Micah Richards mounted a half-hearted protest to referee Alan Wiley after conceding the spot-kick on 27 minutes following a foul on Salomon Kalou.

The England full-back caught the Chelsea man and Wiley had no option but to point to the spot and Lampard beat keeper Andreas Isaksson to claim his eleventh league goal of the season.

City rallied, however, and Barton sent a 20-yard half-volley narrowly wide shortly after his cross into the penalty area had created a headed opportunity for Richards.

Chelsea held out until half-time, though, and the champions ought to have extended their lead early in the second-half when Lampard beat the offside trap to latch onto Arjen Robben's throughball.

The England midfielder lofted the ball over Isaksson's head, but Richards was in the right place at the right time to head the ball back into his goalkeeper's hands.

Pearce attempted to spark his team into renewed action by throwing forwards Ishmael Miller and Georgios Samaras into the fray as Chelsea tightened their grip on the game.

But Cech's goal remained untested and the impression was that the home side could play all night without worrying the Chelsea goalkeeper.

Chelsea substitute Shaun Wright-Phillips, a former City player, almost put the game beyond Pearce's team on 78 minutes when his dipping 25-yard strike hit the crossbar.

Mourinho's team did not need the second goal to seal the game, though, and Lampard's penalty was enough to claim the points and move them to within six points of United at the top of the table.