Ryan Shaw led the way for the top dogs with a hat-trick of tries.
And it was Shaw who opened the scoring after errors and ill-discipline from Dewsbury paved the way for the Robins to set up good field position to exploit.
Dewsbury showed good character early on though and had a couple of tilts at the opposition line before eventually getting on the scoreboard with a strange one-pointer, Lewis Fairhurst’s kick somehow scraping over the crossbar.
However, normal service resumed for Rovers moments later when Andrew Heffernan almost strolled over after penalties had again put Dewsbury on the back foot.
Again Rams rallied but each assault was rebuffed until Hull KR were able to launch a counter-offensive which – once again – ended with a try for Shaw.
Jamie Ellis landed his third conversion of the afternoon and six minutes later Ben Cockayne put Heffernan away to finish well.
Dewsbury looked dead on their feet and by half-time were trailing 36-1.
The Rams looked sprightlier at the start of the second half and were rewarded when Dale Morton got on the end of a grubber kick.
And six minutes later Gareth Potts crossed.
Any thoughts Rams had of reeling in Rovers, however, were dashed when Cockayne crossed and with 10 more minutes Jordan Abdull had his name on the scoresheet.
It was now one-way traffic as Rovers brought up the 50-point mark and ran out comfortable victors.
Hull KR: Cockayne, Shaw, Heffernan, Salter, Oakes, Abdull, Ellis, Mulhern, Jubb, Jewitt, Addy, Clarkson, Blair. Subs: Dockar-Clay, Cator, Clark, Wardill.
Dewsbury Rams: Morton, Potts, Brown, Hooley, Brown, Speakman, Fairhurst, Johnson, Hemingway, Igbinedion, Spicer, Hayes, Glover. Subs: Sykes, Day, Ward, Teanby.
Referee: Tom Grant.