Spurs' lacklustre 0-0 draw at last-place Queens Park Rangers gave the European champions an opportunity to become the nearest challengers to the two Manchester clubs, who are both in action Sunday, and they didn't waste it.
Stoke forward Jonathan Walters endured a disastrous day, twice heading the ball into his own net — in the 45th and 62nd minutes — to set Chelsea on its way before crashing a wild penalty over the crossbar in stoppage time.
Frank Lampard, who converted a penalty, and Eden Hazard, with a thumping 30-yard strike, were the other goalscorers for the visitors to give interim manager Rafa Benitez some respite amid growing disquiet at the direction the club is heading.
"We needed to show character and quality and we did both things," said Benitez, who continues to be jeered by fans angry at his appointment as interim manager in November. "You have to realize the team is doing well.
"The players are happy and training well ... we cannot control what is going on outside the pitch but we do our best on the pitch."
Chelsea is 11 points adrift of leader Manchester United as Benitez's side strives to stay in the title race, but can pull four points clear of Spurs by winning its game in hand — against Southampton on Wednesday.
Tottenham lacked its usual attacking fizz in the stalemate at Loftus Road, ensuring QPR manager Harry Redknapp enjoyed a satisfying reunion with the team that fired him last summer.
Everton and West Bromwich Albion failed to take advantage of Tottenham's slip-up, though, in the fight for Champions league qualification.
Fifth-place Everton was held to 0-0 by Swansea, whose prolific forward Michu was watched by Spain coach Vicente del Bosque after his impressive start to his first season in English football.
West Brom, meanwhile, stayed seventh after conceding three goals in the final eight minutes to lose 3-2 at Reading, which moved two points clear of QPR.
Struggling Aston Villa slipped into the bottom three — and piled the pressure on under-fire manager Paul Lambert — by losing 1-0 at home to Southampton, with Rickie Lambert stroking home the winner from the penalty spot. Wigan moved out of the relegation zone thanks to a 1-1 draw at Fulham.
Newcastle highlighted its need to replace departed striker Demba Ba by drawing 0-0 at Norwich and Sunderland beat West Ham 3-0 for a relieving first win of 2013.
With Man United playing Liverpool and Man City visiting Arsenal on Sunday, all eyes were on the race for the Champions League spots and Chelsea was the big winner in every sense.
They were undoubtedly thankful for Walters' inadvertent interventions — the Ireland international crashed a diving header into the corner to give Chelsea the lead and was then looking the wrong way as he glanced a corner into his own net to make it 2-0.
But Chelsea was worthy of its victory, with Lampard excelling on his recall to the team, missing two great chances before hitting his spot kick down the middle after Juan Mata tumbled in the area. That put him on his own in second place on Chelsea's all-time scoring list, with 194 goals.
Hazard capped a fine away performance with a wonderful swerving effort in the 73rd and there was even time for Benitez to give captain John Terry a run-out as a substitute after a two-month injury lay-off.
Terry actually gave away the penalty with a clumsy foul on Walters, but the forward blew his chance to make amends for his own goals.
"He had a bad day in terms of things not going his way but he was still brave enough to pick the ball up and take the penalty," said Stoke manager Tony Pulis, whose side's 17-match unbeaten run at Britannia Stadium came to an end.
While Chelsea was in the goals, Tottenham struggled to create many chances against QPR, going scoreless for only the third time this season.
Emmanuel Adebayor was left frustrated in his final match before departing for the African Nations Cup with Togo and fellow striker Jermain Defoe also left Loftus Road shaking his head after being denied by two great saves by QPR goalkeeper Julio Cesar.
QPR stayed bottom after Reading's fightback against West Brom but a draw with Spurs soon after a 1-0 win at Chelsea has raised belief about beating the drop.
"That was every bit as good as the performance against Chelsea — we worked our socks off," Redknapp said. "That was the quietest I've seen Gareth Bale for many a year."
Reading was headed to bottom of the table only for a remarkable late rally, with Jimmy Kebe, Adam Le Fondre and Pavel Pogrebnyak scoring in an eight-minute span at Madejski Stadium.
"I'm a little bit shell-shocked," West Brom manager Steve Clarke said.