Winger Rob Worrincy and prop Sam Barlow both scored twice as Karl Harrison’s side cruised to their second half-century of points in a little over a week.
As first-versus-third contests go, this was about as one-sided as they come, Halifax in front inside 10 minutes with tries from Steve Taylor and Rob Worrincy, both set-up by Sean Penkywicz.
The Rams gave notice of their own threat when dual-registered Leeds hooker Liam Hood almost made a score for centre Ayden Faal, before sending Ryan Esders over on the blind side.
Worrincy produced a great leap to pluck Penkywicz’s kick out of the air and dance over by the corner flag for a 14-4 lead.
Dewsbury still looked dangerous in attack at that stage, with Hood often the instigator, and full-back James Craven almost scored close to the half hour, Ashall and Ryan Fieldhouse coming to the rescue in defence.
But the visitors simply had no answer to Penkywicz, who carved them open again just after the half hour, scoring himself to the left of the posts to allow Lee Paterson to kick Fax into a 20-4 lead.
The home side added a try, Sam Barlow crossing twice, both converted by Paterson.
Hood gave Dewsbury a timely filip with a try by the posts, but that was as good as it got for the Rams as Fax posted three scores in five minutes from Ashall, Thackeray and prop Sean Hesketh.
But it was the Rams who gave the ledger a deceptive gloss, the excellent Brad Singleton and the equally impressive Faal both touching down inside the final five minutes.
Halifax: Fieldhouse, Worrincy, Tyrer, Paterson, White, Handforth, Thackery, Hesketh, Penkywicz, Ambler, Robinson, Divorty, Ashall. Substitutes: Casey, Gannon, S. Barlow, Aizue.
Dewsbury Rams: Craven, Akaidere, Esders, Faal, Buchanan, Walker, Spaven, Jones, Hood, Crossley, Spicer, Barker, Tonks. Substitutes: Flanagan, Nicholson, Singleton, Smith.
Referee: J Leahy (RLF).