The lethal combination of Aaron Mclean and Craig Mackail-Smith took their combined tally for the season to 28 - 14 apiece - as Dale were undone at London Road.
Mclean broke the deadlock in the opening period before his strike partner delivered what proved to be the killer blow after the break.
Posh could well have been behind by the time Mclean slammed home with a rasping low 18th-minute drive from the edge of the box.
Lee Tomlin was then only a whisker away from a picture book second goal just after the half-hour, exchanging passes with both Grant McCann and George Boyd before rolling wide.
But Posh did double their advantage eight minutes into the second period when Mackail-Smith finished smartly through the legs of debutant Dale keeper Luke Daniels, who has been signed on an emergency loan from West Brom to solve a keeping crisis.
Visiting boss Keith Hill responded with an attacking double substitution that saw Anthony Elding and Jean-Louis Akpa Akpro introduced - and the latter gave the visitors a lifeline with 11 minutes remaining.
It came in controversial fashion after appearing to take down a long pass with his arm, but there was no disputing the quality of a volleyed finish past keeper Joe Lewis.
Dale continued to press during a tense finish but a fine tackle by home defender Gaby Zakuani on Jason Kennedy just as he was about to pull trigger ensured Posh emerged victorious.
Peterborough 2-1 Rochdale: Match Report - view commentary, squad, and statictics of the game as it happened.
Source: DSG
