Leandro Trossard’s superb late goal gave Brighton a win that dealt a blow to Tottenham’s hopes of finishing in the top four.
Steven Bergwijn then missed a chance to equalise at the start of stoppage time, one of the home side’s rare opportunities.
Spurs stay in fourth, just ahead of Arsenal, while Brighton – in 10th – are on course for their highest-ever top-flight finish.
Graham Potter’s side enjoyed the better of a first half where Spurs looked oddly sluggish despite not having played for nearly a week. But after the hosts appeared to improve in the second half, they were undone by a combination of poor defending and fine skill from Trossard.
The Belgian eluded Eric Dier before opening up his body to send a shot with the outside of his right foot low into the far corner of the net.