Roy Hodgson suffered his second defeat on the bounce as Watford’s wait for a Premier League continues.
Neal Maupay and Adam Webster condemned the home side to their six consecutive defeat at Vicarage Road, leaving them three points adrift of safety having played a game more than Newcastle United.
In a game of few chances, Maupay volleyed past Ben Foster just before the break to give the Seagulls a deserved advantage before Webster poked the ball home 10 minutes from time to make it 2-0.
The Hornets went into the weekend in the 19th place but much of the early optimism after Hodgson guided the club to a first clean sheet in the league this term with a 0-0 draw in his opening match at Burnley appears to be fading.
Watford have now yet to score in the three matches since the former England manager took the helm and have just one point to show for it.
Brighton, however, moved closer to consolidating their place in the top half of the table and remain unbeaten in the Premier League since December 15.
Foster was called into action early on as he made a low save to deny Jakub Moder from 15 yards in the seventh minute.
Brighton maintained their early pressure, with Pascal Gross heading a Moder cross over the bar while Maupay tried his luck from distance and forced Foster to palm the ball away.
Watford had a chance after Emmanuel Dennis was brought down just outside the box by Lewis Dunk, but Dennis sent the free-kick well over the bar.
Just before half-time, Maupay broke the deadlock. Tariq Lamptey fired in a cross and Maupay volleyed it first time into the far corner.
Ismaila Sarr was introduced at half-time in one of two changes made at the break by Hodgson and the Senegal international, who had only taken part in training for the first time on Friday following his Africa Cup Of Nations success, looked to get forward and create chances on his first appearance for Watford since November.
Watford’s best chance of the match came in the 63rd minute when Dennis worked his way into a promising position before unleashing a shot which rattled off the crossbar.
Shortly after, Watford had to be alert to block a Moder cross after the ball ricocheted around the box before falling to the Brighton midfielder, but his shot was blocked.
Marc Cucurella also had a chance to double his side’s lead but his drive from distance was saved by Foster, who had to use his legs to deny the defender.
Brighton’s second came with less than 10 minutes remaining in the match when Webster was able to poke the ball into the back of the net from close range following an Alexis Mac Allister corner.