Manchester United beat Chelsea 1-0 on Sunday to end the champions' 40-match unbeaten Premier League run and cut their lead at the top of the table to six points.
Midfielder Darren Fletcher scored the only goal of a high quality match at Old Trafford, a few miles from where Chelsea were last beaten in the league by Manchester City on October 16, 2004.
Chelsea have 31 points from 12 matches, six ahead of Wigan Athletic who won 2-0 at Portsmouth on Saturday for their sixth win in a row.
United, who ended Arsenal's 49-match unbeaten run last season, climbed to third, 10 points adrift of Chelsea with a game in hand.
United, who had lost their last two matches, scored just past the half hour in an exciting match which they dominated in the first half but were pinned back in the second and survived a string of chances.
Winger Cristiano Ronaldo crossed beyond the far post from the left and Fletcher ghosted in behind the defence to plant a looping header over keeper Petr Cech and defender John Terry and just inside the other post.
"If we can keep it tight behind, which of course in the last few weeks we haven't been able to do, we've always got match winners," United's match-of-the-match Alan Smith said.
"I think the front three today were magnificent, Ruud (van Nistelrooy), Cristiano and Wayne (Rooney)...We have players up front who can win us matches," the midfielder told Sky Sports.
Alex Ferguson, celebrating his 19th anniversary as United manager, said his team sat back too much in the second half but deserved their win.
"When we were going forward we were always a real threat to them," he said. "The best players on the pitch were all from United."
Chelsea manager Jose Mourinho was not too downcast after his side's second defeat of the week following their Champions League loss at Real Betis.
"I think the difference was luck, everyone who participated in the game should be proud, winners and losers...today I'm proud of my team and not afraid of the future," he said.
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Chelsea had their first chance when a superb long ball by Frank Lampard found striker Didier Drogba on the left but his attempted lob was too low to beat goalkeeper Edwin van der Sar.
Left back Asier del Horno shot just wide when he ran in behind the defence to meet Damien Duff's free kick to the far post.
At the other end, Paul Scholes shot just wide after Rooney's cut-back from the left.
Van Nistelrooy should have added to United's tally nine minutes into the second half but fired Fletcher's cutback high over the bar from a very good position.
As Chelsea took control and played largely in United territory for the final half hour, Drogba steered the ball just wide of the post after substitute Eidur Gudjohnsen's shot was blocked.
Van der Sar saved at Lampard's feet from two metres in the 68th and Del Horno raced in to shoot just over but United hung on for only their second home league win of the season.
In an earlier match, James Beattie's 16th-minute goal gave Everton a 1-0 win over Middlesbrough, their first home league victory of the season. Everton climbed two places to 16th, five points and three spots behind Middlesbrough.
Arsenal beat Sunderland 3-1, Liverpool won 2-0 at Aston Villa and Manchester City lost 2-1 at Fulham on Saturday. Tottenham Hotspur visit Bolton Wanderers on Monday.
