The Whites were beaten 2-0 in the south coast, with goals from Pascal Gross and Danny Welbeck enough to ensure that the hosts picked up a valuable win.
The result leaves Marcelo Bielsa’s men 11th in the table with just four games left to play, and could represent a significant dent in their hopes of a top-half finish.
Speaking after the game, the Argentine coach was quick to deliver a blunt assessment of where his side came up short against the Seagulls.
He said: "We didn't play well.
"The victory for the opponent was fair. We created very little danger and it was difficult for us to recover the ball. The game was hard with the height of their centre-backs. We couldn't avoid them initiating the play, nor could we overcome them trying to get in behind.
"In the middle sector of the pitch we were trying to find variety to get in behind them.
"Yes, there was very few [chances], that's true. It wasn't because [Patrick Bamford] was isolated. It was because the ball couldn't reach the final third. I pay more attention to the construction of our offensive game."
Next up for Leeds is a clash against Tottenham Hotspur in Saturday's early kick-off.
Spurs beat Sheffield United 4-0 on Sunday evening.
We’ve gathered the best of today’s Premier League transfer rumours involving Leeds United and the rest of their top flight rivals below...
7. Campbell touts Willock deal
Kevin Campbell has backed Newcastle United to sign Joe Willock permanently from Arsenal at the end of the season. The ex-striker claims that the midfielder already has 'God-like' status in the north east. (Football Insider) (Photo by Clive Brunskill/Getty Images) Photo: Clive Brunskill
8. Hammers make approach for Bissouma
West Ham have approached Brighton with an enquiry about midfielder Yves Bissouma ahead of the summer transfer window. (Sunday People) (Photo by Mike Hewitt/Getty Images) Photo: Mike Hewitt
9. Euro elite chase White
PSG and Borussia Dortmund are set to battle Manchester United for Brighton defender Ben White this summer. (The Sun) (Photo by Mike Hewitt/Getty Images) Photo: Mike Hewitt