Andy Whing converted Deane Smalley's right-wing cross to give goalkeeper Josh Lillis no chance with a brilliant close-range scissor kick eight minutes into the second half.
James Constable, who had come on as a half-time substitute, lashed in a second from Jon-Paul Pittman's pass for his 13th goal of the season.
And Alfie Potter made it three in stoppage time, chipping deftly over Lillis after a quick break that began from a dreadful Rochdale corner.
The impressive finishes were out of character with a tepid affair between two mid-table teams whose hopes of reaching the play-offs had disappeared some time ago.
Smalley went close with a powerful angled drive in the second minute that Lillis beat out, and Potter screwed his follow-up shot wide.
Dale, who had come into this game on the back of just one defeat in nine, threatened only fleetingly.
George Donnelly had an early opportunity with a free header at the far post from Bobby Grant's cross, but he nodded tamely into the arms of keeper Luke McCormick.
Michael Rose's ambitious 22-yard volley from a corner cleared the bar by some distance, and young sub Reece Gray fired into the side netting.