Arsenal beat Manchester United 1-0 to keep the Premier League title race wide open on Sunday with Aaron Ramsey's second-half winner cheered almost as loudly by Chelsea fans.
United stayed top of the table with 73 points from 35 matches but, with three games left, remained just three points clear of champions Chelsea who they play at Old Trafford next Sunday.
Chelsea, who beat Tottenham Hotspur 2-1 on Saturday, trailed United by 15 points two months ago but if they win next week they would go ahead on goal difference.
Arsenal, who maintain a slim chance of winning the title, are third with 67 points but manager Arsene Wenger conceded that their challenge was over last week and the win was more about keeping alive their hopes of finishing third.
"We had a good performance, disciplined with fighting spirit," Wenger told reporters. "Until we scored, I think we controlled it completely, then we came under more pressure.
"I still make United favourites, they are at home. For us to have a small chance it's in our interest for Chelsea to win."
The only goal of a match Arsenal largely dominated at a sun-drenched Emirates Stadium came after Robin van Persie cut the ball back to Ramsey who found the corner of Edwin van der Sar's net after 56 minutes.
Ramsey, making only his second Premier League start of the season because captain Cesc Fabregas was injured, scored his first league goal since before he broke his leg 14 months ago.
Arsenal, who had lost six of their previous seven matches to United, could have made the breakthrough earlier when referee Chris Foy missed a clear handball by defender Nemanja Vidic as Van Persie was poised to head in a cross.
United could also have had a penalty late in the game when Gael Clichy appeared to rake his studs down substitute Michael Owen's leg and sent him sprawling in the area.
"It's too big a game not to get the decisions right," United manager Alex Ferguson told Sky Sports. "It balances out in that respect but I think it was difficult to see that one (Vidic's handball) but the one at the end, Clichy knew, he put his hands up in horror.
"Obviously, it gives Chelsea a major chance now and that's what happens when you get these decisions. They got one at Old Trafford last season so that's the worry now.
"But in terms of ability -- a game at Old Trafford, the supporters will be ready for it -- and so will our players."
Earlier, Liverpool, who share the record of 18 championships with United, beat Newcastle United 3-0 to move into fifth place, maintaining their climb up the table under manager Kenny Dalglish.
A goal from Maxi Rodriguez after 10 minutes, a Dirk Kuyt penalty after 59 minutes and a strike from Luis Suarez lifted Liverpool into the Europa League qualifying berth, pushing Spurs down to sixth.
"It was a difficult day for both sets of players as it was really hot," Dalglish said.
"After we took the lead, they put us under pressure with set plays and crosses, but I thought we coped very well and in the second half we tightened up a wee bit and caught them twice for two goals. I think we deserved to win, but it was a difficult game for us.
The clubs were meeting for the first time since Andy Carroll moved from Newcastle to Liverpool for 35 million pounds in January, but the striker only came on for the last 20 minutes and did not go close to scoring.
"With the Andy Carroll factor maybe it added a wee bit of spice for them," Dalglish said.
Birmingham City drew 1-1 with Wolverhampton Wanderers at St Andrews, leaving Wolves deep in relegation trouble. They remain second bottom on 34 points, a point from safety. Birmingham are 15th on 39 points.