Tottenham repelled a second-half onslaught as Andre Villas-Boas masterminded their first away win over Manchester United since 1989 with a 3-2 victory.
Jan Vertonghen and Gareth Bale gave the visitors a deserved half-time lead, but not for the first time at Old Trafford in recent years Tottenham were hit by a fierce second-half fightback.
However, Clint Dempsey scored in between efforts from Nani and Shinji Kagawa to keep Spurs in front, and after Wayne Rooney and Michael Carrick had struck the frame of Brad Friedel's goal, Tottenham clung on for the final whistle.
There were only two minutes on the clock when Vertonghen strode between Nani and Carrick, drove into the United box and found the corner of Anders Lindegaard's net. The Belgian's shot did take a significant deflection off Jonny Evans, but Vertonghen deserved his slice of good fortune for the adventure he had shown to get into United's penalty area.
Rather than sting United into action, the early goal merely encouraged their visitors. Bale sped past Rio Ferdinand and into the box before beating Lindegaard rather too easily to make it 2-0.
Having resisted the temptation to name Rooney alongside Robin van Persie for the first time, Ferguson could delay the inevitable no longer and brought on the England man for Ryan Giggs at the break. The move triggered a burst of three goals in four minutes.
Rooney provided the assist for Nani's close-range effort, curling a low cross to the near post that invited the clinical finish. Van Persie could claim the credit for United's second as he threaded a precise pass through the Tottenham defence that allowed Kagawa to beat Friedel.
Crucially, though, Tottenham struck their third goal in between United's brace, Bale once again exposing poor defending as he surged forward, and when Lindegaard was unable to hold the Welshman's low shot, Dempsey was on hand to slot home the rebound.
Rooney thudded a brilliant free-kick against a post before Van Persie's dismal attempt to finish off a Carrick pass suggested again that it might not be United's day.
William Gallas clattered into a post such was his determination to keep Nani's far-post cross away from Rooney, then Friedel turned away a Paul Scholes thunderbolt. Carrick's header almost sneaked in but dropped against angle of post and bar instead and United failed to find an equaliser before the final whistle.