They were set on course by striker Andy Kirk who scored twice, taking his season's tally to five, while Martin Smith and Pedj Bojic grabbed the others while Junior Mendes was always a handful.
Rovers included five former Northampton favourites in their line-up, as well as head coach Paul Trollope but for them it was a case of unhappy returns.
Kirk opened the scoring from the penalty spot after 33 minutes after he had been brought down himself by Craig Hinton and he picked himself up to tuck the penalty just inside Scott Shearer's right hand post.
Kirk was twice denied by Shearer's legs in the first half but he made it two nil just before break when he deflected a Josh Low header past the Rovers' goalkeeper.
Rovers could have made it 2-1 just after the break when Steve Elliott's header flew just wide but Martin Smith made it 3-0 after 39 minutes after a perceptive through ball had released Low behind the defence.
Lee Harper produced an excellent save to deny Rovers' leading scorer Junior Agogo with 18 minutes left and a minute from time Pedj Bojic made it 4-0 when he directed a looping header over Shearer from a cross by substitute from Mcgleish.
It could have been worse for Rovers and if Junior Mendes had been a little luckier with a clinical turn and shot late in the game which would have rewarded the striker for a lively performance in the week that his loan period from Huddersfield was extended to three months.
Rovers could also point to a second half effort from Elliott which flew just a fraction wide.