(CNN) -- English Premier League leaders Chelsea moved three points clear of Manchester United at the top with a hard-fought 2-1 victory over bottom side Portsmouth at Stamford Bridge on Wednesday night.
But it needed a late penalty by Frank Lampard to earn the victory, their first in five games.
Nicolas Anelka put them ahead when he converted Alex's cross in the 23rd minute but Avram Grant's battlers stunned their hosts with a shock equalizer from Frederic Piquionne six minutes after halftime.
Pompey looked set to frustrate Chelsea, but Marc Wilson mistimed a challenge on Branislav Ivanovic and Lampard converted from the spot 11 minutes from time.
It leaves them with 40 points from 17 games with Manchester United on 37.
Chelsea manager Carlo Ancelotti was relieved his side had broken their victory drought but admitted it had been far from easy.
"We lost composure for 15 minutes," he told Sky Sports News.
"But we finished the game well and deserved to win.
"We did a good job, but not a beautiful job," he added.
Arsenal are in third place with 32 points from 16 games, but missed a chance to reinforce their challenge by being held 1-1 at Burnley, failing to build on their excellent victory at Liverpool on Sunday.
Spanish international midfielder Cesc Fabregas put Arsenal ahead early in the match at Turf Moor, but Burnley, who have an impressive home record, leveled after Thomas Vermaelen fouled Andre Bikey to concede a penalty.
Graham Alexander converted the spot kick in the 28th minute and it was the hosts who came closest to a winner when Chris Eagles hit a post.
Arsenal are edging fourth-placed Aston Villa on goal difference, but their north London rivals Tottenham Hotspur took closer order in fifth, two points behind, after a superb 3-0 home win over big-spending Manchester City.
Inspired by winger Aaron Lennon, who set up Niko Kranjcar for the opener and Jermain Defoe early in the second half, Tottenham dominated at White Hart Lane.
Kranjcar scored his second and the third late in the match to seal the victory.
Liverpool hit back from their home defeat to Arsenal on Sunday with a much-needed three points secured at Anfield with a 2-1 win over Wigan.
Celebrating the 50th anniversary of the arrival of legendary manager at the club, Liverpool were ahead thanks to a ninth-minute goal from David Ngog.
A late second from Spanish striker Fernando Torres, who started the match on the bench, steadied nerves for Rafael Benitez's men, but Jason Scotland hit the bar for the visitors and Charles N'Zogbia netted in injury time.
Liverpool, desperate for a top four finish to secure Champions League football next season, are up to sixth with the win.