Dewsbury ran in six unanswered first half tries as they produced some exhibition rugby to cut Rochdale open.
The Rams were ruthless in attack and raced into a 16-0 lead inside the opening quarter.
Dewsbury signalled their intentions early in the game when James Glover launched an attack with a storming run, which took them close before stand in scrum half Michael Knowles stabbed the ball to the in-goal area and forced a drop out.
The Rams launched another attack and Paul Sykes produced a beautifully weighted kick to the left. Dale Morton outjumped his opposite number to pluck the ball out of the air and force his way over for the try.
Rochdale had a scrum on half way but dropped the ball and Glover was first to react, scooping it up and racing away for a try which Sykes converted.
Rochdale again knocked on close to their own line under severe pressure from the Rams.
They moved play quickly right and Sykes produced a lovely pass for Rob Worrincy to force his way over and Sykes added an excellent conversion from wide out.
Rochdale had Gary Middlehurst sin-binned for a high tackle and the Rams took full advantage as they moved play left from the resulting penalty and Aaron Brown crashed over, with Sykes again converting.
With Rochdale still down to 12 men, Dewsbury piled on the pressure and Dominic Speakman produced a deft kick to the in-goal area for Brown to pounce for his second try.
Dewsbury capped a magnificent first half with the pick of their seven tries.
With Rochdale attacking deep in Rams territory, a kick went to ground and Worrincy scooped up the ball close to his own line.
The winger stepped past a would be tackler before running wide and racing up the right touchline, outpacing the entire Hornets defence on a terrific 90 metre run to the line. Sykes hit the post with his conversion attempt but the Rams had all but wrapped up victory as they went into the break leading 32-0.
If the Rams attacking display had earned coach Neil Kelly’s praise in the first half, their defensive effort was equally as impressive after the break as Rochdale piled on the pressure.
Hornets were awarded six second half penalties to nil but time and again were repelled by the superb Rams defence.
Having soaked up the pressure, Dewsbury grabbed a 62nd minute try when Sykes’s lovely pass sent full-back Josh Guzdek racing through to score next to the posts, with Sykes converting.
Rochdale replied with a consolation try when former Ram Luke Adamson gathered a short pass and raced behind the posts, with Harvey Livett converting, but it took none of the gloss off a superb away performance by the Rams.
Rochdale Hornets: Kay; Cross, Johnson, Hurst, Massam; Palfrey; Yates; Adamson, Moores, Hadden, Middlehurst, Mitchell, Livett. Subs: Maneely, Hatton, Taira, Moran.
Dewsbury Rams: Guzdek; Worrincy, Glover, Hallett, Worrincy; Sykes, Knowles; Sheriffe, Ward, Teanby, Spicer, Crowther, Brown. Subs: Speakman, Walshaw, English, Everett.
Referee: Nick Bennett.