Josh Hardcastle, Jason Walton and Scott Turner each scored two tries and Cory Aston kicked six goals in second-placed Featherstone’s sixth straight victory.
They were far too good for the Rams who never recovered after being 16-0 down after 17 minutes.
Rovers coach Jon Sharp said: “I was delighted with the football we played.”
James Lockwood plunged over from close range for an eighth-minute try to put Featherstone on their way.
Ian Hardman and Hardcastle then put in Misi Taulapapa before John Davies’s kick led to Hardcastle scoring.
The Rams flickered briefly when Shaun Squires supplied a lovely pass to send in Lewis Fairhurst at the corner but they were soon under the cosh again.
Walton powered over for a 30-yard try from Hardman’s pass and Turner then bagged two touchdowns in three minutes.
Anthony Thackeray and Walton made the opening for the wingman’s first score and he quickly struck again with a slick finish after James Glover fumbled Aston’s high kick.
Rovers increased their lead to 42-4 early in the second half when Walton scored his second and Frankie Mariano also went over, both players making successful comebacks after lengthy injury lay-offs.
Squires scored Dewsbury’s second try from Tom Hemingway’s grubber kick and Glover converted but they finished well beaten.
Hardcastle scored his second before Rovers completed the rout six minutes from time with a try from Leeds Rhinos dual registered forward Jack Ormondroyd.
Disappointed Dewsbury coach Neil Kelly said: “You’ve got to come and put up a fight and I think we put up a whimper.”
Featherstone Rovers: Hardman; Turner, Walton, Hardcastle, Taulapapa; Thackeray, Aston; Moore, Carlile, Cooper, Mariano, Davies, Lockwood. Subs: Griffin, Wildie, Tagg, Ormondroyd.
Dewsbury Rams: Morton; Fairhurst, Squires, Walshaw, Glover; Speakman, Kain; Sherriffe, Hemingway, Adamson, Igbinedeon, Ollett, Brown. Subs: Adamson, Ward, Hayes, Tonks.
Referee: Tom Grant (Leeds).