(CNN) -- English Premier League leaders Chelsea smashed seven goals past hapless Sunderland on Saturday, while second-placed Manchester United kept up the pressure with a 3-0 victory at home to Burnley.
Chelsea lost four key players to the Africa Cup of Nations, but showed they still have plenty of firepower following a 7-2 demolition of visiting Sunderland.
England midfielder Frank Lampard scored two goals, as did France striker Nicolas Anelka on his return from injury, while Germany midfielder Michael Ballack, France winger Florent Malouda and defender Ashley Cole also netted.
Coach Carlo Ancelotti was delighted as his team, missing strikers Didier Drogba and Solomon Kalou plus key midfielders Michael Essien and Jon Obi Mikel, remained one point ahead of United having played one less game than last season's champions.
"I think that was maybe the best performance this season," the Italian told reporters. "We played very well until the end of the match. We started the game very well. I'm very happy because it's an important time for us.
"Without the African players we maybe could have some problems. I always said I have a fantastic squad and today other players played very well, especially Juliano Belletti in a new position for him, so it is a good moment for us."
The win was slightly tarnished by an ankle injury to England fullback Cole, whose goal was the 18,000th in Premier League history, while captain John Terry was taken off at halftime as a precaution with the Londoners already 4-0 up.
Sunderland scored two consolation goals through substitute Bolo Zenden, a former Chelsea player, and prolific striker Darren Bent, but Steve Bruce's side were left in 12th place after eight league games without a win.
Manchester United moved onto 44 points from 21 games after a 14th league victory this season, but Burnley's defense held out for more than an hour in new manager Brian Laws' first game in charge.
Bulgaria striker Dimitar Berbatov finally broke the deadlock in the 64th minute as he atoned for several earlier misses with a clever flick for his seventh goal of the season.
He was also involved in the second goal five minutes later, with England forward Wayne Rooney following up after his strike partner was denied by Burnley goalkeeper Brian Jensen.
New signing Mame Biram Diouf marked his home debut with a goal at the end as he headed Antonio Valencia's cross past Jensen.
United manager Alex Ferguson later revealed that Berbatov, who has been struggling with knee problems, may need to have surgery.
"He played through it today but he could have come off at half-time. We will have to look at it again on Monday and see what the situation is," Ferguson said.
Fourth-placed Manchester City failed to close the gap on Arsenal, who travel to Bolton on Sunday, after losing 2-0 at mid-table Everton.
City manager Roberto Mancini suffered his first defeat in five games since taking over from the sacked Mark Hughes.
South Africa midfielder Steven Pienaar scored for the second successive match with a superb free-kick in the 36th minute, while France striker Louis Saha then doubled the lead in first-half injury-time with a penalty after City defender Micah Richards was ruled to have pulled his shirt.
Everton hit the woodwork twice in the second half through midfielders Marouane Fellaini and Tim Cahill as City pressed forward in search of a goal.
Tottenham remained in fifth place after being held 0-0 at home by second-bottom Hull, who had goalkeeper Boaz Myhill to thank for a series of superb saves.
Spurs boss Harry Redknapp, who faces court action by tax authorities next month, was left frustrated in his 500th Premier League match as a manager -- though his team equaled their club record of five consecutive clean sheets.
Liverpool's under-pressure manager Rafael Benitez also suffered a disappointing end to a miserable week as his team, who were knocked out of the FA Cup by second division strugglers Reading, were held 1-1 at 10th-placed Stoke.
The visitors, missing the injured key trio of Steven Gerrard, Fernando Torres and Yossi Benayoun, led in the 57th minute through Greece defender Sotirios Kyrgiakos' first goal for the club, but German center-back Robert Huth snatched a point for Stoke with seconds remaining.
Last season's runners-up were left in seventh place on 34 points, struggling to qualify for next season's Champions League let alone mount a title challenge.
Wigan moved out of the relegation zone with a 2-0 victory at fellow strugglers Wolverhampton, as both teams ended the match with 10 men.
Second-half goals from new signing James McCarthy and Charles N'Zogbia came after Wolves goalkeeper Marcus Hahnemann saved Hugo Rodallega's penalty.
Home defender Richard Stearman and Wigan midfielder Hendry Thomas were sent off in either half.
Bottom club Portsmouth's home clash with in-form Birmingham was called off due to a waterlogged pitch.