A hat-trick of tries from Ben Galea in his 100th appearance for Rovers helped to maintain their push for a play-off place by exploiting the latest round of turmoil in Wrexham.
Crusaders gave as good as they got in the first half, but could not find an answer to the Australian second-rower's destructive running in the left-hand channel, especiallyoff the shoulder of Michael Dobson.
Two of his tries came as part of the Robins' three-try burst in eight minutes at the start of the second half and the Welsh side never recovered from that. It has been, to put it mildly, an interesting week in the short but eventful history of the Crusaders. No sooner had they made an expansive gesture of confidence in the future by signing a high-class, if ageing, player such as Keith Senior than they were suspending seven of their current roster for boozing in the build-up to a match.
They were lined up in the stand in their best collars and ties, like naughty schoolboys waiting to be summoned by the headmaster.
Throw in the two Hull KR players currently suspended by their club for alleged misdemeanors and you could justify calling this the Disciplinary Derby.
Unusually for them this season, Crusaders made rather a promising start, building some pressure and going close to an opening try through both Tony Martin and Gareth Thomas, the latter of whom later went off with a suspected broken arm.
Then, however, they failed twice in as many minutes to make the right decisions in defence and found themselves 12 points down. Jake Webster's pass to Sam Latus yielded the first try and a lovely short ball from Dobson to Galea the second.
Crusaders had a one-man advantage for 10 minutes when Jason Netherton was sin-binned for a late challenge on Michael Witt, but they failed to capitalise on it, both Lincoln Withers and Elliot Kear spilling the ball with the line beckoning.
They continued to dominate when Rovers were back up to strength and finally got their reward when Vince Mellars' pass gave Kear just enough space to squeeze in at the corner.
When Frank Winterstein wrestled his way over five minutes later, it was only fellow Australian Clinton Schifcofske's inability to add a second difficult conversion that kept Rovers in front at half-time.
Unfortunately, that was as good as it got. A series of handling mistakes at the start of the second half led to Shaun Briscoe getting over.
Galea's dummy and footwork produced another try and he ran off Dobson again for his third. Clint Newton and Dobson completed the damage, but Crusaders' coach, Iestyn Harris said that he was proud of the efforts of his depleted side.
"Their willingness to work for each other was there for all to see," he said. "The other seven will be back in training on Monday with a point to prove, but this group really dug in together."
Rovers' Justin Morgan echoed that assessment. "You've got to give creditto Crusaders," he said. "I thought they were very spirited."
The Robins have their own internal distractions, but Morgan dead-batted the rumours that have him going to Castleford next season and the issue of when his two suspendedplayer will be available again.
Crusaders Schifcofske; Reardon, Thomas, Mellars, Kear; Martin, Witt; O'Hara, Withers, Bryant, A James, Winterstein, Flowers. Substitutes used Williams, Burke, Grant, J James.
Hull KR Briscoe; Fox, Webster, Wellham, Latus; Green, Dobson; Vella, Fisher, Netherton, Newton, Galea, Murrell. Substitutes used Wheeldon, Taylor, Hodgson, Lovegrove.
Referee T Alibert (France)