Frank Lampard and Nicolas Anelka scored twice as Chelsea turned on the style to move to 48 points, one more than champions Manchester United who were made to sweat for a 3-0 home victory over Burnley.
Arsenal, third on 42, visit Bolton Wanderers on Sunday while three of the teams battling for fourth place had days to forget as Manchester City lost 2-0 at Everton, Tottenham Hotspur drew 0-0 at home to Hull City and Liverpool drew 1-1 at Stoke City.
Chelsea had won just two of their previous six league games but clicked into gear immediately against an injury-hit Sunderland side described by their manager Steve Bruce as "inept".
"It was a fantastic performance, maybe the best this season, and we need to continue to play," manager Carlo Ancelotti told Sky Sports News.
"It was a funny game, we had so many opportunities in the last third of the field it was almost embarrassing," said United manager Alex Ferguson. "We didn't score and then from a breakaway Burnley could have scored.
"At Old Trafford you need patience to wear teams down and when we got the goal I felt it was coming."
Roberto Mancini's four-game winning run since he took over at Manchester City ended when resurgent Everton outplayed his side at Goodison Park.
The win took Everton's unbeaten league run to seven games and was a wake-up call for Mancini, who introduced Robinho as an early substitute and then took the 32 million pounds Brazilian off in the second half after another ineffectual performance.
Sotiris Kyrgiakos's scrappy 58th-minute goal seemed likely to give them a much-needed lift after their FA Cup defeat by Reading on Wednesday but Stoke's Robert Huth equalised in injury time to leave manager Rafa Benitez frustrated again.
