Tottenham 's Premier League title ambitions suffered a major blow as Marcus Rashford's goal gave Manchester United a narrow victory at Wembley to maintain caretaker manager Ole Gunnar Solskjaer's perfect start.
Rashford beat Tottenham keeper Hugo Lloris from a tight angle in the 44th minute as rejuvenated United claimed a sixth win from six matches since former striker Solskjaer stepped in following the sacking of Jose Mourinho.
United's Spanish keeper David De Gea produced a series of superb saves to deny Dele Alli, Harry Kane and Toby Alderweireld after the break as United hung on for a first away league win against Tottenham since 2012.
Solskjaer's side remained in sixth spot but are now level on 41 points with Arsenal while Tottenham have 48 points in third place, nine behind leaders Liverpool and two behind champions Manchester City who face Wolverhampton Wanderers on Monday.
In a wide-open first half full of attacking football, Kane had a goal disallowed for the hosts but United, with Jesse Lingard, Anthony Martial and Rashford forming a rapid attacking trio, were dangerous every time they broke forward.
The first goal always looked like being vital and it arrived for United just before the break when Rashford made ground down the right and with no other option he drove into area and fired a shot that Lloris got a firm hand to but could not keep out of the net.
Lloris redeemed himself with two saves from Paul Pogba early in the second half but after that it was all about the excellence of De Gea as Spurs, roared on by the majority of the 80,000 Wembley crowd, desperately sought an equaliser.
First he saved Kane's close-range header, then blocked Alli's shot with his legs after the midfielder went through one-on-one, before making a stunning reaction save to deny Toby Alderweireld's near-post flick.
Kane's free kick was saved acrobatically by De Gea and with five minutes remaining he saw another goalbound effort cannon off the shins of the Spaniard.