Ian Sharps' first Burton goal earned them a 1-0 win as they eventually wore down Northampton at the Pirelli Stadium.
The struggling visitors' only chance of note saw Ben Tozer firing down Dean Lyness' throat, with their promotion-chasing hosts otherwise dominant.
Chris Hussey's left-footed cross from the right wing found Billy Kee unmarked at the far post, but his header was easily claimed by ex-Brewer Matt Duke.
Jimmy Phillips' cross to the far post was then nodded back in by Phil Edwards and Kee's weak header was saved.
Phillips also got on the end of McGurk's inviting cross, but saw his diving header saved.
Kee had two great chances early in the second-half, both set up by Phillips, but twice shot wide, the first from just six yards out, before Robbie Weir volleyed well over from close range and McGurk cut inside and curled a shot over.
It looked like caretaker Andy King would take a point back to Northampton, but late on Matty Palmer's driven corner was powered home by a towering Sharps.