Mark Hughes' own goal and a strike from Scott Hogan gave Keith Hill's high-flying outfit all three points against a Shrimps side who started the day just one point behind them in the table.
Morecambe hit back with Padraig Amond giving them a glimmer of hope with a well-taken goal a minute from time but it proved too little, too late for Jim Bentley's side, who suffered a third defeat in four league games.
Rochdale always looked the livelier side but were kept at bay until just after the hour when Hughes diverted a left-wing cross past his own goalkeeper from close range.
The visitors then added a second just two minutes later when Hogan produced a fine piece of skill to weave his way past Andy Wright before curling a superb right-footed effort past Barry Roche.
The game started at a great pace with both sides firing efforts on goal inside the first minute. Alex Kenyon fizzed a shot over from the edge of the area before Hogan tested Roche with a long-range effort.
Chances were then at a premium, with Rochdale the closest to breaking the deadlock as Graham Cummins drew a save from Roche after 41 minutes with a close-range shot from Ian Henderson's pull back.