Frank Lampard scored the decisive goal from penalty to restore Chelsea's three-point lead in the Premier League with a 2-1 home win against bottom club Portsmouth on Wednesday.
Champions Manchester United had pulled level on points on Tuesday after beating a second-string Wolverhampton Wanderers 3-0 in manager Alex Ferguson's 900th league game in charge.
Chelsea's Frank Lampard (C) celebrates with team mates after scoring against Portsmouth during their English Premier League soccer match at Stamford Bridge in London December 16, 2009.
Arsenal failed to match the pace, held 1-1 by a spirited Burnley at a rain-lashed Turf Moor to move ahead of Aston Villa on goal difference in third place with a game in hand but eight points off the lead.
Chelsea have 40 points, Manchester United 37 and Arsenal 32.
Chelsea's Nicolas Anelka (R) celebrates with team mate Salomon Kalou after scoring against Portsmouth during their English Premier League soccer match at Stamford Bridge in London December 16, 2009.
Chelsea, without injured top scorer Didier Drogba, dominated from the start at a chilly Stamford Bridge against opponents led by their own former manager Avram Grant. Nicolas Anelka put the Blues ahead midway through the first half, slotting the ball into the bottom right corner past goalkeeper Asmir Begovic who started as a replacement for David James.
Portsmouth refused to give in and were rewarded five minutes after the break when Jamie O'Hara's free kick hit the wall and fell for Frederic Piquionne to score the equalizer into the roof of the net.
Lampard converted home the penalty in the 79th minute to pull off a three-point lead at Premier League for Chelsea.