Clint Dempsey beery-eyed after scoring the third goal for Spurs
Clint Dempsey's first goal for Tottenham earned the club a first victory at Old Trafford since 1989 as Spurs ruthlessly punished some poor defending from Manchester United.
Jan Vertonghen swept the visitors ahead before Gareth Bale streaked away from Rio Ferdinand to drive in a second.
Wayne Rooney came off the bench to set up a Nani volley, but Dempsey then tapped in after Bale's shot was saved, reports the BBC.
Shinji Kagawa scored and Rooney hit the post from range but Spurs held on.
Andre Villas-Boas saw his side take an early lead when Belgian defender Vertonghen exchanged passes with Bale, was ushered inside by Ferdinand and hit a low shot which took a big deflection off Jonny Evans to wrongfoot Anders Lindegaard.
Tottenham again exposed Ferdinand's lack of pace with a superb second, as Bale charged from inside his own half to leave the former England captain in his wake before firing in right-footed.
Rooney made his return to the Premier League after a month out at the break and instantly made an impact, crossing from the right for Nani to stab in.
But Dempsey restored Spurs' two-goal cushion straight away.
Ferdinand was again caught out - by Jermain Defoe this time - and he passed inside for Bale to thrash in a drive which Lindegaard could not hold and Dempsey was on hand to finish.
Kagawa then scored the third goal in as many minutes when he collected Robin van Persie's through pass and steered in a left-footed shot which went in off the far post.
Rooney then smashed a free-kick against the post and Michael Carrick headed against the crossbar but United could not find an equaliser.