Town kept in the hunt for the Play-Off places with a first ever win at the Amex Stadium, thanks to second-half goals from Tommy Smith and Daryl Murphy.
The opener came on the hour, Murphy heading on from a corner and Smith in the right place to find the net for the second successive game.
Murphy then took his tally to 10 for the season when he headed past Tomasz Kuszczak after Jonny Williams had shown some magic outside the Brighton box to conjure up the opening.
The win keeps Town right in the frame for the top six with massive home games against Derby and Nottingham Forest to come this week.
Anthony Wordsworth replaced the injured Cole Skuse in Town’s only change from the side that went down to Wigan last weekend, Frank Nouble on the bench after recovering from a hamstring problem.
Good work by Paul Anderson created an opening on six minutes but his cross beat the supporting Williams, then Brighton had a gilt edged opening when Jesse Lingard got clear after a long ball from
Bruno Saltor but his shot lacked power and Dean Gerken saved comfortably.
Town responded with a Stephen Hunt free-kick cleared by Gordon Greer, then Christophe Berra headed back from Aaron Cresswell’s corner and Luke Chambers forced Kuszczak in a save from close range.
Chambers then fed Murphy who cut inside but his left foot strike was blocked in a bright start for Blues.
The dangerous Saltor was causing problems down the Town left though and from another whipped in cross, Leonardo Ulloa sent a header at Gerken.
Wordsworth volleyed wide at the nearpost from Cresswell’s neat delivery, then Williams thought he had given Town the lead on 25 minutes after the ball had broken to him off Murphy but the offside flag was raised.
Tommy Smith rescued Town with a terrific challenge to rob former Blues’ loanee Keith Andrews inside the box before Saltor picked up a first yellow card for a foul on Hunt.
Kuszczak had an anxious look over his shoulder after Cresswell’s shot took a big deflection off Saltor and landed on the roof of the net, the Seagulls hitting back with Lingard firing wide after being set up by Stephen Ward in the last clear chance of a first-half that was fairly evenly matched in goalscoring opportunities.
Gerken produced a top class save to keep out Lingard’s strike as the second-half got underway with the Seagulls on the front foot, Hunt replying at the other end but he couldn’t keep his shot down from 20 yards.
Ulloa headed wide after Saltor and Andrews linked up down the right before Blues got the breakthrough on the hour, Murphy winning Hunt’s corner and Smith heading in from six yards out.
Brighton made an immediate change with Kazenga LuaLua on for Jake Forster-Caskey, Saltor firing well wide as the Seagulls looked for a response.
Ulloa headed wide from Lingard’s cross, Luke Hyam then in the right place to deny the Manchester United loanee before Town made a double change with Paul Green and Jay Tabb joining the action, Anderson and Hunt making way, with Solly March also on for Lingard.
Smith was yellow carded for a foul before Blues made it two on 80 minutes, Williams the creator and Murphy finding the net with a header from eight yards.
Williams received a standing ovation from the 1700 strong Blue Army when he was replaced seven minutes from time – the smile on the Wales international’s face summing up Town’s day as Blues went into a crucial week on a winning note.