Fulham thrashed a woeful Manchester United side 3-0 at Craven Cottage to inflict the champions' fifth Premier League defeat of the season.
Goals from Danny Murphy (pictured), the excellent Bobby Zamora and Damien Duff gave Roy Hodgson's men victory against a United side that found themselves completely outplayed, both individually and collectively.
Chelsea can go six points clear of United if they beat West Ham on Sunday. Fulham stay ninth but consolidate their position in the top half of the table.
Sir Alex Ferguson may point out that he was missing four fifths of his first choice back five - Edwin van der Sar, Nemanja Vidic, Rio Ferdinand and John O'Shea - while Jonny Evans, Wes Brown, Rafael Da Silva and Owen Hargreaves were also unavailable.
However, only the Scotsman will know why his solution was to organise his side into a 3-5-2 formation with his one senior defender - Patrice Evra - playing wide on the left side of midfield.
A back three of Michael Carrick, Darren Fletcher and Ritchie De Laet would hardly be worthy of relegation strugglers, let alone championship contenders, and Fulham naturally set about using Zamora's physical presence up front.
The big striker, who has hit a rich vein of goalscoring form, was a constant menace, and he set up a glorious chance for Zoltan Gera on 17 minutes, knocking the ball down only to see the Hungarian's volley saved brilliantly by Tomasz Kuszczak. But five minutes later Fulham were in front.
Murphy carved out a reputation for scoring against United when he played for Liverpool, and is doing the same in the white of Fulham.
The midfielder found the net in the 2-0 win against United in March, and was similarly deadly when presented with an opportunity by Paul Scholes, who dawdled in possession and was robbed by the Fulham skipper.
Nobody closed Murphy down, and he beat Kuszczak from outside the box with a precise shot that found the bottom-left corner.
With Darron Gibson looking far from the finished article in central midfield, and Michael Owen totally ineffective up front, the visitors created little, and a frustrated Wayne Rooney was reduced to firing speculative long range shots.
Fulham looked the more creative and dangerous side, and might have increased their lead through Zamora just after the half-hour: the striker glanced a header just wide after fine build-up play by Clint Dempsey and Gera.
Alex Ferguson could have been forgiven a half-time blast of the hairdryer, but whatever he said during the break, it is safe to say it did not work.
Within 20 seconds of the restart, Fulham doubled their lead as Duff crossed from the right, Dempsey headed the ball down and an unmarked Zamora lashed his volley powerfully into the net from eight yards - his 10th goal of the season.
The customary second half United surge failed to materialise, and they were arguably even more hopeless going forward than at the back.
Their attacks lacked pace, purpose and invention, while Fulham showed them how to do it with slick passing moves that oozed quality.
The best of the visitors' half-chances fell to Rooney, who hit a diagonal shot that went narrowly wide of the far post and just missed the onrushing Antonio Valencia.
Fulham scored a deserved third on 75 minutes and Zamora, naturally, was at the heart of it. He chested down a Murphy free-kick, flicked it deftly on to Duff and the Irishman buried a low left-foot volley.
The chants of 'Zamora for England' when the striker came off in stoppage time do not seem so fanciful any more - a trip to the World Cup for Fulham's number 25 certainly seems more likely than a successful United title defence if they play as badly as this.