Callum Robinson had opened the scoring for the hosts just after the break. It was a well worked goal for the Baggies as Matt Phillips' header was directed into the path of Kiaran Grant.
He outpaced Albion' s Dan Burn and squared for Robinson to convert with a right footed shot.
Cedric Kipré's dismissal on 69 minutes for a foul on Leo Trossard proved decisive. The defender was already on a yellow when he hauled down the Belgian.
Albion exploited the extra space and it was second half substitute Jakub Moder that levelled with an angled left footed drive into the top corner.
Moder then turned provider when his cross was well left by Trossard and Neal Maupay rifled home at the near post to beat former Albion man David Button.
Scroll down and click through to see who shone and who struggled for Graham Potter's team.
1. Kjell Scherpen 7
Debut for the Dutch goalkeeper, who joined the Seagulls in a £4.2m move from Ajax in July. Did little wrong and had little to do other than the goal. Good distribution.
2. Joel Veltman 6
Solid as usual from the Dutchman. Defended in his usual calm manner with sound possession. Took no risks and did little going forward
3. Shane Duffy 6
Decent in defence but should have scored when he blazed a volley over the bar from close range midway through the second half
4. Dan Burn 8
Solid at the back tried to get forward when he could and volleyed one long range effort over the bar.