The visitors ended with ten men after David Vaughan was sent off with six minutes remaining for a second yellow card, but in truth the game was over by then and Town should have won far more easily.
Stead gave Town exactly the start they wanted when he found the net with just 29 seconds gone.
The forward pulled down a loose ball 30 yards out, made room for a shot and fired home from 20 yards with his left foot beyond Matt Gilks' right hand.
Gilks was one of five changes Ian Holloway surprisingly made to a team which won at Middlesbrough in midweek, but they could have been level two minutes later when Evatt's header from a Barry Bannan corner was headed off the line by Grant Leadbitter.
After a quiet spell, Town stepped up the pressure as half-time approached with Gilks saving from Jon Walters and Stead before Damien Delaney headed a Garvan corner against the bar, but they doubled the lead just before the break when Colback ran clear onto Stead's pass and coolly slotted beyond Gilks.
Walters shot wide from a Leadbitter pass as Town went in search of a killer third after the break and sub Keith Southern shot over from a Gary Taylor-Fletcher pass, before Evatt gave them hope with a far post header from another fine Neal Eardley cross.
That came with 23 minutes remaining, but four minutes later Garvan won a corner which Leadbitter swung in and McAuley jumped to head home from close in with Gilks flapping at the ball.
After that it was a case of how many Town could get as they repeatedly sprung the Blackpool offside trap as the visitors threw bodies forward in search of a way back into the game.
Walters got through and crossed for Jaime Peters to blaze over and then Stead played Walters clean through and although he rounded Gilks, Stephen Crainey got back to make a last-ditch tackle.
Walters got clear but over-hit his cross to an unmarked Stead, who then raced onto a Walters flick-on to lob over Gilks but wide of goal in another missed opportunity for the hosts.
Vaughan saw red for a foul on Colback, having previously been cautioned for chopping down Walters, but he could have joined in an early bath by both Leadbitter and Crainey who were fortunate to be let off by ref Phil Crossley with bad challenges after being booked earlier.