Alan Pardew celebrated his belated first Premier League win as West Brom boss after two headers from corners.
But skipper and Man City transfer target Jonny Evans, who struck the opener, hobbled off crocked in the closing stages.
Pardew had Albion practising their set-pieces after eight games without a win in the top-flight under him.
It stretched West Brom's winless run to a club record 20 league matches, losing 10 of them.
But that dire run was deservedly ended here thanks to an early header from Evans and Craig Dawson's after the break.
Albion made a storming start as Evans, back in place of Gareth McAuley after missing the FA Cup win at Exeter, headed them into the lead.
He struck in the fourth minute when Matt Phillips' corner was cleverly flicked on by Jay Rodriguez and Evans headed in from close-range. Brighton battled back into the contest as they enjoyed plenty of possession.
But Albion might have doubled their lead before the break when Dawson went clear only for Mat Ryan to be quickly off his line to save. Albion made it 2-0 in the 55 minute from another slick corner.
This time Chris Brunt's left-footed outswinger was met with a powerful downward headed by Dawson for his first of the season.
Brighton, who had not scored in their five previous away games, wasted a great chance in the 66 minute when Anthony Knockaert blazed over.
WBA: Foster 7, Dawson 8 (Nyom 81, 6), Hegazi 7, Evans 8 (McAuley 84, 6), Gibbs 7, Phillips 7, Barry 8, Krychowiak 7, Brunt 7, Rondon 7, MOTM Rodriguez 8 (Livermore 79, 6)
Brighton: Ryan 6, Bruno 6, Duffy 6, Dunk 6, Bong 6, Stephens 8, Propper 6 (Kayal 76, 6), Knockaert 6, Gross 6 (Baldock 78, 6), Izquierdo 4 (March 45,6), Murray 6 Referee: Martin Atkinson Attendance: 25,240
We’re mid way through the first half and Jonny Evans’ goals separates these two sides.
How will Brighton respond?
Chris Hughton has warned his Brighton players not to be fooled by West Brom’s woeful run of form and perilous league position.
Hughton’s Seagulls travel to The Hawthorns on Saturday with their struggling opponents on a 20-game winless streak in the Premier League stretching back to August.
Baggies boss Alan Pardew has so far failed to spark an upturn in results since replacing Tony Pulis in late November, taking just four points from a possible 24 to leave his team languishing in 19th place.
Brighton have already contributed to West Brom’s misery this season, inflicting their first defeat with a 3-1 win at the Amex Stadium in September.
That result was the Seagulls’ first top-flight victory for 34 years, but, as they go in search of a double, manager Hughton was keen to remind of the threat posed by the Baggies.
“We certainly can’t be sidelined by a difficult period (for West Brom),” said Hughton.
“What we have to look at is the quality they have in the squad and that means at any given time they can win football matches.
“I think what they have is good options and that makes them very dangerous.
“It’s a game that they will want to win. The fact that they’re at home against a team that they would see as not one of the top teams, it’s a team that they are capable of beating and we have to be very guarded with that.”
Brighton’s preparation for the game has been hit by a couple of injury setbacks.
On-loan Chelsea forward Izzy Brown has been ruled out for the rest of the season with knee ligament damage suffered in Monday’s FA Cup win over Crystal
Palace, while midfielder Steve Sidwell, who has not featured so far this campaign because of a back problem, sustained a small fracture to his foot in training.
Hughton, who has already let out-of-favour winger Jamie Murphy depart for Rangers this month, wants to prevent a gap appearing in his squad in the wake of Brown’s absence, but does not expect any imminent arrivals.
“We have to make sure that we don’t have a void in there,” Hughton added.
“Probably the reason why I say we’re not close (to making a signing) is you’ve brought somebody in or you haven’t, you’ve done a deal or you haven’t and
I’ve been involved in enough windows to be very, very close to something that doesn’t happen. We’re working very hard.”
In terms of more players leaving the club, Hughton said there have been plenty of enquiries from clubs wishing to take defender Connor Goldson on loan.
Goldson, who underwent heart surgery last year, has made just four appearances in all competitions this season, serving as an understudy to impressive centre-back pairing Lewis Dunk and Shane Duffy.
Hughton would like the 25-year-old to make a temporary move, although he wants to bring in defensive cover beforehand.
“There’s always been interest in Connor so we would be very, very confident that, if we were in the position that we want to be in to allow him to go out,
that there would be takers for him.
“Connor’s been here for a good period with us now, but it’s probably a year and a half since he was playing regularly and we want him to play regular games.”