Joao Pedro struck a late winner as Brighton put a dent in Aston Villa’s Champions League hopes at the Amex Stadium.
The Brazilian headed home a rebound in the 87th minute after his penalty was saved by Robin Olsen.
Pascal Gross had an earlier effort for the hosts ruled out for offside by the Video Assistant Referee (VAR), while Villa captain John McGinn was also judged to be inches ahead of the Brighton defence before scoring at the other end.
Unai Emery’s fourth-placed side remain seven points clear of Tottenham, who have two games in hand and visit Liverpool on Sunday.
Having suffered a disappointing loss to Olympiakos in the Europa Conference League on Thursday night, Villa missed the chance to strengthen their hold on fourth with two matches left.
They were sluggish throughout and Brighton looked to have taken a deserved lead in the 68th minute when Gross met a Pedro cross with a clever finish, but VAR ruined his celebrations.
The Seagulls had found Villa keeper Olsen – replacing the injured Emiliano Martinez – in fine form, but kept pressing.
When winger Simon Adingra went to ground in the box under a challenge from Ezri Konsa, referee Robert Jones pointed to the spot.
It was almost in keeping with the game that Pedro had his penalty pushed away by Olsen, but the striker was sharp enough to nod home the rebound.
Roberto de Zerbi’s side moved up to 11th in the table after ending a disappointing six-match winless run and claiming their first home success against Villa since 1980.