Kevin Phillips scored a goal in each half as Blackpool overcame fellow play-off hopefuls Brighton, who were reduced to 10 men early in the second half.
Joe Mattock headed Brighton in front but Ian Evatt side-footed home the leveller from Stephen Crainey's cross.
Blackpool were ahead by half-time through a deflected effort from Phillips, then Gonzalo Jara was sent off for a lunge on Keith Southern.
Phillips completed victory by diverting in Gary Taylor-Fletcher's drive.
The victory lifts Blackpool back into the Championship top six at the expense of Brighton, who are a point behind Middlesbrough in sixth after their first league defeat of 2012.
Veteran Phillips crafted the first opportunity for namesake Matt to scuff wide but the hosts were soon behind. Craig Mackail-Smith had a header brilliantly saved by Matt Gilks and, from the resulting corner, Mattock rose unmarked to power in for Brighton.
Ian Holloway's men quickly applied pressure in search of an equaliser and Adam El-Abd was forced to clear Keith Southern's deflected shot off the line.
Phillips drew a superb diving save from Peter Brezovan in the 35th minute and, moments later, Blackpool finally broke through as Evatt finished.
Their dominance began to tell as Tom Ince burst into the box to find Phillips, who failed to make a clean contact, but a deflection off Jara was enough to take the shot beyond Brezovan.
The frantic pace continued after half-time, but goalmouth action was at a premium and Brighton's task became harder as Jara was dismissed for his late challenge on Southern.
The visiting supporters wanted referee Simon Hooper to even the numbers up when Neil Eardley hacked down Ashley Barnes, 25 yard from goal. He received a booking and Gilks looked on anxiously as Vincente's free-kick grazed the upright.
Gus Poyet's side continued to push and Gilks held on from a Gordon Greer header, but when Taylor-Fletcher reacted quickest to Southern's blocked drive, Phillips sealed the win.