Christian Eriksen scored after just 11 seconds at Wembley – the fastest ever Premier League goal against Manchester United.
A Phil Jones own goal put Spurs two up before the break and United never looked like getting back into it.
Alexis Sanchez made his Premier League debut for the Red Devils but struggled to influence the game.
Indeed, Spurs could have won by a larger scoreline had Dele Alli and Harry Kane not gone wide with decent chances.
And Marouane Fellaini endured the embarrassment of being subbed off six minutes after coming on in the second half – the Belgian immediately heading to the changing rooms.
The win comes on the day Spurs announced the signing of Lucas Moura from PSG.
The winger was paraded on the pitch before kick off.
United had already wrapped up the bulk of their transfers before deadline day.
Full match report to follow…