Andy White fired a goal on his debut as Crewe secured their third win on the trot.
Further strikes from Kenny Lunt and Michael Higdon earned them the three points at Gresty Road against a Brighton side who lost for the first time in two months on their travels.
Brighton sub Albert Jarrett reduced the deficit with a goal late on and Mark McGhee's side had two further chances at the death which could of salvaged a point, but Alex ran out worthy 3-1 winners in the end.
Captain Lunt opened the scoring with a fantastic free-kick in the ninth minute after Steve Jones had been fouled by Paul Reid inside the visiting 'D'.
The midfielder curled the ball around the wall into the far corner and continued his influence with a fine pass which almost put David Vaughan in on goal, only for Charlie Oatway to make a last-gasp interception to save the day.
Jones wasted the chance to add to Crewe's lead in the 23rd minute when after ceasing on Adam Hinshelwood's weak headed backpass. He volleyed straight at Michels Kuipers' legs.
Crewe did get their second in the 33rd minute when White seized on a loose ball inside the box and volleyed home from ten yards.
Brighton enjoyed plenty possession in the first half, but there was little end product. Leon Knight wasted their best chance after the referee's assistant erred, allowing him to run in on goal when he looked at least a couple of yards offside.
The former Chelsea youngster's touch let him down and Anthony Tonkin got back to clear the ball for a corner.
It should've been a comfortable passage to three points for the Railwaymen, but they were guilty of some lapses at the back in the second half.
Veteran Oatway should've reduced the arrears on 50 minutes when Knight picked him out with a cross but, unmarked on the edge of the six-yard box, he headed over the bar.
Crewe appeared to have sealed the game in the 68th minute when after Kerry Mayo had crashed into the back of Jones, Lunt chipped a free-kick to the far post, where Justin Cochrane's header was saved by Kuipers.
A game of pinball ensued with Vaughn sending it back across the box and Cochrane pulling it back from the by line before Higdon applied a close-range finish. Brighton's' players protested that the ball had gone out of play before Justin Cochrane had retreived it, but to no evail.
They were given a glimmer of hope when substitute Jarrett seized on an underhit back pass from Billy Jones and ran into the box and tucked the ball under keeper Ben Williams.
Another Albion sub Jake Robinson was gifted two chances in stoppage time. He latched on to Mayo's lob, but trickled the ball the wrong side of the post with WIlliams stranded, then he shot straight at the keeper's leg after Tonkin's poor clearance header exposed Crewe again.
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