Ole Gunnar Solskjaer continued his perfect start as Manchester United manager as his side earned a 1-0 victory at Wembley.
Tottenham must wonder what they will have to have done to get past David De Gea, who was in inspired form in the United goal.
The Spaniard made 11 saves in total - more than any other goalkeeper in a match this season - as he kept United on course to collect all three points.
He was beaten once all afternoon, but was saved by the linesmans flag, as Harry Kane's goal was ruled out for offside.
Marcus Rashford then got United's noses in front, racing clear onto Paul Pogba's pass to fire past Hugo Lloris.
Tottenham threw everything they could at United in the second half, but just could not score.
First Kane was denied by the feet of De Gea, before he turned away Alli's header.
He then thwarted both players again, before makin a great reaction save from Toby Alderweireld.
The barrage of attacks continued, as De Gea turned away another Alli effort, and again stopped Kane's strike with his feet, Solskjaer has now won all five of his Premier League matches in charge of United - and they are chasing ground on the top four.