Ander Herrera’s winner sent Manchester United into a record-equalling 20th FA Cup final and condemned Tottenham to their eighth successive defeat at this stage of the competition.
Spurs started at a ferocious pace and fully deserved the early lead they took after only 11 minutes when Dele Alli slid home a finish from Christian Eriksen’s cross after Davinson Sanchez’s long pass opened up Manchester United’s defence.
Jose Mourinho’s side survived the siege and levelled on 24 minutes, Wembley specialist Alexis Sanchez rising to direct an athletic header across Spurs keeper Michel Vorm from Paul Pogba’s perfect cross for his eighth goal in eight appearances at the stadium.
Eric Dier’s deflected shot hit the post on the stroke of half-time but Spurs had lost vital momentum and Herrera’s crisp low finish just after the hour set up an FA Cup final date for United with Chelsea or Southampton on 19 May.
It left Spurs suffering more FA Cup semi-final pain and with a losing sequence stretching back to their win in the last four against Arsenal here in 1991 – and Pochettino still without a trophy after four seasons at the club.