BRIGHTON: Kuipers, El-Abd, McShane, Butters, Lynch, Hammond, Reid (Robinson 81), Carpenter, Frutos, Carole, Hart.
Subs Not Used: Mayo, Kazim-Richards, Tommy Elphick, Chaigneau.
LEEDS UTD: Sullivan, Kelly, Kilgallon, Butler, Crainey, Douglas, Derry, Miller (Hulse 69), Lewis (Pugh 82), Blake (Healy 78), Cresswell.
Subs Not Used: Bennett, Walton.
Leeds went into the game on the back of four successive wins, but have yet to beat Brighton in the Championship following relegation and slipped further behind leading pair Reading and Sheffield United.
Gary Hart secured Brighton's first win since Boxing Day to dent Kevin Blackwell's promotion push, and produce a result that must have hit a few punter's 'fixed odds coupons'.
Blackwell made just one change from the side that drew at Wigan in the FA Cup with Richard Cresswell replacing Rob Hulse.
Brighton stole a march in the 10th minute when Reid converted Alexandre Frutos' left-wing cross, their early breakthrough coming after Dean Hammond had seen his header hit the post.
Leeds responded via a Jonathon Douglas volley that was blocked by defender Adam El-Abd, who then cleared Blake's shot off the line.
Blake almost hauled Leeds level with a fine free-kick in the 30th minute. The striker's 25-yard effort was curling into the top corner, but at full-stretch Kuipers turned the ball away and Cresswell headed Lewis' subsequent corner over the crossbar.
Leeds wrestled more possession as the first half progressed with Shaun Derry prominent and Cresswell saw his 25-yard shot blocked by Guy Butters before the Whites drew level seven minutes before the break.
Lewis was fouled in the penalty area by Reid and Blake stepped forward to slam home his seventh goal of the season.
Both sides were struggling to carve out further chances and Blackwell sent on Hulse for Miller in a bid to snatch all three points with 20 minutes left. But Brighton regained the lead. Reid escaped down the right and his cross into the penalty area was thumped into the top corner by Gary Hart in the 80th minute.
Blackwell sent on David Healy for Blake and Danny Pugh for Lewis soon after but Leeds were growing frustrated and Hulse was booked for dissent.
Healy's 35-yard free-kick hit the wall and Cresswell's header from Kelly's cross whistled over the crossbar as Leeds slipped to their fifth away defeat of the season.