The Cumbrians made a perfect start when Karl Hawley picked up Zigor Aranalde's throw and turned in the box to fire in his fourth goal of the season.
Hawley's strike put Carlisle in the driving seat and they took advantage of some slack Brighton play to fire in a non-stop bombardment of crosses and long balls.
Man-of-the-match Peter Murphy twice went close for the home side before his defensive colleague Kevin Gray doubled Carlisle's advantage after 31 minutes.
Aranalde's looping free-kick was headed straight back to him and the veteran full-back smashed a low cross into the six-yard box where Gray was on hand to bundle the ball passed Michels Kuipers.
Kevin Gall and Simon Hackney nearly combined for a third Carlisle goal as the Cumbrians dominated proceedings.
Brighton almost pulled a goal back with their first shot at goal when the lively Dean Cox curled just wide from the edge of the box.
The visitors then had a clear sight on goal but found Carlisle keeper Keiren Westwood in top form.
Hitman Gary Hart rose unchallenged to head low towards the corner of the net but Westwood tipped the goalbound effort out for a corner.
A reshuffle at half-time from the visitors, including shifting Hart to full-back, paid dividends as Carlisle struggled to find their first-half rhythm.
A dour second half was lit up when Carlisle strung together an 11-pass move before adding a third.
Aranalde played a first-time ball to Hawley whose inch perfect cross was met by the head of Hackney at the far post.
A late rally from the Seagulls saw them grab a consolation after a Murphy slip allowed Alex Revell to smash the ball past Westwood.
But it was all too late for the visitors and their 267 fans as they made the long, long trip back to the south coast.