The latest of late goals from Tottenham denied Ajax a place in the Champions League final and set up a showdown with Liverpool.
With seconds left, Lucas Moura found the net with a precise finish to complete another semi-final comeback and his own hat-trick.
Ajax's players slumped to the turf as their night unravelled.
The Dutch side had already won 1-0 away in London last week, leaving Spurs with much to do.
And they set about making that deficit even more yawning.
Young captain Matthijs De Ligt had already scored a towering header on the night Ajax knocked out Juventus.
Spurs Struggle
Within five minutes, the Netherlands international had headed in the home side's opener at the Johann Cruyff Arena after poor Spurs marking.
Tottenham did fashion chances and hit the post through Son Heung-Min. His cross from the left struck the base of the post, catching Ajax keeper Andre Onana out.
Ajax's Matthijs de Ligt, top left, scores the opening goal during the Champions League semifinal second leg soccer match between Ajax and Tottenham Hotspur at the Johan Cruyff ArenA in Amsterdam, Netherlands, Wednesday, May 8, 2019. (AP Photo/Peter Dejong)But Erik Ten Hag's team extended their lead at the other end just 10 minutes before half-time.
Ex-Southampton midfielder Dusan Tadic found space down the Spurs right flank and cut it back for Hakim Ziyech to sweep in a superb second goal.
Tottenham came close after half-time when Dele Alli tested Onana who reacted well to deny the England player's first-time effort at the back-post.
Tottenham's Lucas Moura, left, scores his side's opening goal during the Champions League semifinal second leg soccer match between Ajax and Tottenham Hotspur at the Johan Cruyff ArenA in Amsterdam, Netherlands, Wednesday, May 8, 2019. (AP Photo/Martin Meissner)And four minutes later, Tottenham were level on the night. Onana initially made a great save to deny Fernando Llorente. But quick feet and quick thinking from Moura after a scramble in the box saw the Brazilian finish well.
That left Spurs needing just one goal to ahead on away goals.
But Spurs did find the net on 54 minutes. Alli raced through and left it for Lucas Moura to finish it off from close range.
And four minutes later, Tottenham were level on the night. Onana initially made a great save to deny Fernando Llorente. But quick feet and quick thinking from Moura after a scramble in the box saw the Brazilian finish well.
That left Spurs needing just one goal to ahead on away goals.
Twelve minutes from time, Ajax hit the post through Ziyech.
Spurs came close with three minutes left on the clock as Ajax hung on.
Jan Vertonghen headed onto the bar, before Ajax cleared the follow up off the line.
But as the seconds ticked down and hope began to be extinguished, Moura found the net to secure progress on away goals.
And after Liverpool's epic comeback last night, it's been a competition of second leg comebacks.
