A superbly taken David Lopez volley sent Albion into the play-off places for the first time this season.
The solitary strike made it back-to-back wins for the Seagulls and four games unbeaten, in a hard-fought encounter only marred by an injury to in-form midfielder Andrew Crofts.
With both sides beginning slowly, the opening 20 minutes was a cagey affair with the only chance falling to the visitors – however Keith Andrews was on hand to clear off the line.
As the game wore on, Albion began to take control of proceedings and Darren Randolph had to be alert in the Birmingham goal as he turned David’s effort around the post.
Clearly in the ascendancy and, with half-time approaching, the hosts were unfortunate not to take the lead as Randolph pulled off two fine saves from Kazenga LuaLua in quick succession.
The first, a long-range effort, was followed up by another trademark drive after Leo Ulloa had shown some neat control in the build-up.
Albion started the second half on the attack and were rewarded on the hour mark when David netted his first-time volley from a tight angle.
The move initially began when Crofts hit the post before Ulloa’s follow-up effort was blocked. The ball then fell to the Spaniard who, with the outside of his foot, drove home a swerving first-time effort.
Albion’s lead was almost doubled a few minutes later as Crofts’ long-range effort was turned around the post following the introduction of new signing, Jon Obika.
David went close again with a quarter of an hour to play, cutting inside before curling an effort just wide of the Blues goal, before Crofts suffered what appeared to be a knee injury and was replaced by Andrea Orlandi.
With only ten minutes left on the clock, the visitors threw men forward in search of an equaliser but Albion held firm, earning a well-deserved win over a Birmingham side previously unbeaten in ten games.