LONDON: Chelsea moved three points clear of Manchester United at the top of the Premier League as Frank Lampard's late penalty clinched a 2-1 win over Portsmouth on Wednesday.

Carlo Ancelotti's side were in danger of failing to win for the fifth successive match in all competitions when Portsmouth's Frederic Piquionne cancelled out Nicolas Anelka's first half opener.

But Lampard, making his 300th league appearance for the Blues, held his nerve to drive home a spot-kick with 11 minutes remaining and reestablish his team's lead over United, who had beaten Wolves to draw level on points 24 hours earlier.

Ancelotti can take heart from Chelsea's ability to grind out a win when the fates seemed to be conspiring against them, but this was another less than convincing display.

Pompey boss Avram Grant received a warm reception from Chelsea's fans on his first return to the Bridge since being sacked in 2008, but he was always facing an uphill struggle to depart with the points.

Grant, whose team are bottom of the league, must have breathed a sigh of relief to see Didier Drogba sidelined after suffering a back injury in training this week.

Salomon Kalou came in from Drogba, while Ricardo Carvalho paid the the price for Chelsea's recent defensive woes and was dropped for Brazil centre-back Alex.

With Drogba out, Anelka had to be at his best and the France striker forced Portsmouth goalkeeper Asmir Bergovic into action early on with a low shot from the edge of the penalty area.

Kalou should have put Chelsea ahead from the resulting corner but somehow headed over from point-blank range after Michael Ballack flicked on.

Chelsea took the lead in the 23rd minute as Anelka showed Kalou how to deliver the knockout blow.

Alex was the unlikely provider, popping up on the right wing to muscle his way past Marc Wilson and drive a low cross to Anelka, who side-footed past Begovic via the near-post.

Grant's decision to play Piquionne as a lone striker gave Chelsea's back-four an opportunity to rediscover their composure after leaking 10 goals in four games.

But they still looked shaky at times and Piquionne, shooting from just inside the penalty area, forced Petr Cech to make a sprawling save in the 34th minute.

Alex may not have cured Chelsea's defensive ills, but he certainly added some pep to their attack and went close to scoring with a ferocious free-kick that flashed past the far-post.

Ancelotti had called on his side to concentrate better when defending set-pieces but Kalou appeared not to have heeded the warning.

He let Tal Ben Haim escape his attentions at Jamie Hara's free-kick and the former Chelsea defender headed over when he should have scored.

After controlling the first-half, Chelsea surrendered their advantage in the most unfortunate manner in the 51st minute.

O'Hara's free-kick was too close to the Chelsea wall and hit Kalou, but the ball then rebounded off Cole before falling perfectly for the unmarked Piquionne to lash past Cech.

It was a freak goal but Chelsea were rattled and it took a fine tackle from Cole to deny Kevin-Prince Boateng.

Ancelotti sent on Joe Cole for the injured Deco, then introduced Florent Malouda and young forward Fabio Borini soon after that.

Finally Chelsea recovered their rhythm well enough to regain control in the closing stages.

Begovic had to be alert to save when Ben Haim nearly turned Malouda's cross into his own net, then Lampard drew a good stop from the Portsmouth keeper.

They broke Portsmouth's resistance in the 79th minute. Serbian defender Branislav Ivanovic poked the ball past Wilson and the centre-back conceded a penalty with a wild lunging challenge.

Lampard stepped up to crash the spot-kick straight down the middle for his first goal since October.