Victory left the Dons one point behind second-placed Preston, while the result ended Dale’s pursuit of a play-off place.
Karl Robinson’s men served notice of their intent early on when Dele Alli’s volley from 25 yards smashed against the inside of the post and across face of Dale goalkeeper Jamie Jones’ goal.
The visitors went one better in the 15th minute. Andy Cannon was dispossessed by Dean Bowditch and Samir Carruthers weaved his way into the area and slotted a neat finish wide of Jones.
Rochdale passed up a gilt-edged opportunity to level when Scott Tanser and Ian Henderson combined to tee Callum Camps up for a sitter – but he screwed his finish wide from eight yards.
And Dale paid the price for that miss when the Dons doubled their lead in the 29th minute. Carruthers picked out Bowditch on the edge of the penalty area and his first-time curling shot past flew beyond Jones.
The home side grabbed themselves a lifeline in the 65th minute when Henderson crossed for Peter Vincenti to convert from close range.
But substitute Daniel Powell ended hopes of a Rochdale comeback when he squeezed a finish past Jones from the tightest of angles.
Henderson made it 3-2 after 86 minutes when he side-footed past Dons goalkeeper Dean Martin, but the visitors held on for victory.