Charlton came from behind to inflict Albion's first away defeat since September.
Leo Ulloa had given the Seagulls a first half lead, and scored late on, but Lawrie Wilson’s brace and Yann Kermorgant’s free-kick consigned Oscar Garcia’s men to a 3-2 defeat.
On another day it could have been a different story, as Albion – backed by over 2,000 travelling supporters – controlled large portions of the game, hit the woodwork twice and had an effort cleared off the line.
Andrew Crofts showed the Seagulls’ intent as he shot over with just 70 seconds on the clock and Keith Andrews wasn’t far off from connecting with Ulloa’s cross as Albion started confidently.
Oscar’s side had controlled the flow of the game and Ulloa’s return to the starting line-up was justified on 22 minutes when he turned inside the Charlton box before guiding a left-footed strike past Ben Alnwick.
The hosts attempted to hit back immediately as Dale Stephens was beaten to the ball by the fist of Peter Brezovan before Cameron Stewart fired into the Jimmy Seed Stand.
Albion reaffirmed their grip on the game with Crofts looking immense in the middle, driving the Seagulls forward at every chance, and he had an effort from distance that was comfortably held by Alnwick.
However just as it looked as if Albion were going to push on, the hosts struck against the run of play. A loose ball fell kindly to Wilson in the box and he made no mistake in levelling matters.
Simon Church then shot over for the Addicks but it was still Oscar’s side looking more comfortable on the ball, and Liam Bridcutt whisked a fierce effort narrowly wide.
There were penalty appeals from the hosts as Church went down under a challenge from Andrews but the officials were not convinced and the half ended a goal apiece.
The second half started in blistering fashion and ten minutes in the hosts got their noses in front. An unfortunate ricochet off Crofts landed once more into the path of Wilson who fired his and Charlton’s second.
Ulloa scuffed wide for Albion and substitute Ashley Barnes headed over as Oscar’s side searched for an equaliser. The Seagulls did find a way past Alnwick but Ulloa’s bullet header was cleared off the line by Stephens as the hosts continued to frustrate Albion.
The afternoon got worse for Oscar and his side as Yann Kermorgant’s exquisite free-kick curled into the top corner to extend the Addicks’ advantage, giving the Seagulls a mountain to climb.
But Albion didn’t give up hope and were once more inches from the net as Barnes and Inigo Calderon both cracked the woodwork in quick succession. Barnes’s deflected strike dropping onto the post and Calderon’s placed effort on the rebound found the same fate.
Ulloa prodded home from close range in injury time but the hosts held on for the victory.