Craig Mackail-Smith's extra-time header gave Brighton a shock victory over a strong Sunderland side in the second round of the Carling Cup.
Mackail-Smith, who had earlier hit the woodwork, met Alan Navarro's cross at the back post to grab the winner.
Sunderland's best effort saw Stephane Sessegnon denied by Casper Ankergren.
But the Championship side created more chances and could have had a penalty when Keiren Westwood appeared to foul Inigo Calderon in the box.
Defeat adds to what has been a difficult start to the season for Black Cats boss Steve Bruce, whose revamped side have failed to win any of their first three games.
Bruce made only three changes from Saturday's disappointing defeat in the north-east derby with Newcastle, bringing in three more of his summer signings in Westwood, David Vaughan and Craig Gardner.
Sessegnon almost gave the visitors the perfect start when he pounced on a loose ball inside the area but drilled his shot wide.
At the other end, Gus Poyet's men should have taken the lead when Westwood failed to gather a long-range Mackail-Smith effort, but Ashley Barnes blasted his follow-up effort over.
It appeared Sunderland were slowly taking control of the game but they struggled to create openings while, at the other end, Brighton began to get their reward for their slick passing football.
Westwood denied Barnes and Mackail-Smith's shot hit the inside of the post and rolled back across the face of goal after he ran on to Calderon's pass.
The home fans reacted angrily when referee Andy D'Urso booked Calderon for diving when he went to ground after rounding Westwood in the box.
But they went home happy after Mackail-Smith finally broke the deadlock with his third goal since his £2.5m summer move from Peterborough.