London:Leader Chelsea stormed to a 7-2 victory in the Premier League over Sunderland on Saturday, while second-place Manchester United labored past Burnley and Manchester City lost for the first time under Roberto Mancini.
Frank Lampard and Nicolas Anelka both scored twice as Chelsea dismantled an injury-hit Sunderland side to remain a point ahead of United with a game in hand.
"We have just given maybe our best performance of the season," Chelsea manager Carlo Ancelotti said. "This is how we should continue to play from now until the end of the campaign."
Defending champion United took until the second half to get going against Burnley, with Dimitar Berbatov, Wayne Rooney and Mame Biram Diouf eventually clinching a 3-0 win.
Man City had won its last four league matches _ three since Mancini took charge _ before losing 2-0 at Everton and handing fourth place to Tottenham, which drew 0-0 with Hull.
It was also a frustrating day for Liverpool, which conceded a 90th-minute equalizer to draw 1-1 at Stoke to remain seventh.
Chelsea, though, delivered a masterclass in attacking football at Stamford Bridge to show it can prosper without African Cup of Nations quartet Didier Drogba, Michael Essien, John Obi Mikel and Salomon Kalou.
Anelka took just eight minutes to start the rout after rounding goalkeeper Marton Fulop. Florent Malouda shrugged off two challenges and struck into the bottom corner in the 17th.
The third came five minutes later when Ashley Cole sprinted onto John Terry' lofted ball and chipped Fulop. Lampard volleyed home from six meters (yards) before the break.
The Blues remained as formidable in the second half, with Ballack home in the 52nd, Anelka slotting into an empty net from the edge of the area in the 65th and Lampard nodding in a seventh in the 90th.
Sunderland managed two consolation goals through Bolo Zenden and Darren Bent. Steve Bruce's side has failed to win in its last eight league games.
At Old Trafford, Burnley threatened to thwart United again, having beaten the champions at the start of the season. Burnley held out until the 64th when Berbatov's shot flicked off Michael Duff and flew past goalkeeper Brian Jensen.
Rooney added his 16th goal of the season shortly afterward and the substitute Diouf netted his first United goal.
"We could have been embarrassed," United manager Alex Ferguson said. "We had a number of opportunities to punish them in the final third but there was a bit of nervousness and anxiety about our game."
While United chases a fourth-straight title, last season's runners-up are just trying to land one of the four Champions League spots.
And Liverpool looked set to move up the standings when Sotirios Kyrgiakos scrambled in his first goal for the club in the 57th minute. But Robert Huth scored the late leveler for Stoke, three days after Liverpool conceded in stoppage-time as it was knocked out of the FA Cup by second-tier club Reading.
"It feels like a defeat," Kuyt said. "We aren't playing the best football at the moment but I thought we fought really hard for this result, and to concede in the last minute and even miss a great chance in the last minute is unbelievable."
In the Everton matchday program, manager David Moyes accused Man City of having "no class" in its pursuit of defender Joleon Lescott last August.
And City lacked class on the pitch Saturday to match the value of its side. Mancini's problems started in the eighth when Roque Santa Cruz, who has been troubled by knee problems, limped off and was replaced by Robinho.
Steven Pienaar made the breakthrough in the 36th, curling a free kick beyond Shay Given at the goalkeeper's near post. Louis Saha's scored Everton's second from the penalty spot in first-half stoppage time amid City protests after the French striker's shirt was tugged by Micah Richards.
Wigan moved four points clear of the relegation zone as James McCarthy and Charles N'Zogbia scored to claim a 2-0 win at Wolverhampton.
Wolves goalkeeper Marcus Hahnemann also saved a penalty from Hugo Rodallega. Both sides ended with 10 men as Wolves defender Richard Stearman and Wigan midfielder Hendry Thomas were sent off.
A week after the schedule was virtually wiped out by freezing conditions in England, only Portsmouth's home match against Birmingham fell victim to the weather as the thaw led to a waterlogged pitch.