Rams scored four tries to three in a 20-14 success, but Rovers could take heart from a strong fightback after being 10-0 down inside 22 minutes.
The scores were level coming up to the hour mark and there were just two points in it until Rams grabbed the game’s seventh try with four minutes left.
Both teams are in transition under a new coach and clearly have a lot of work to do before their league campaigns begin next month, but there were positives to take from their second pre-season game.
Rams boss Lee Greenwood, whose team lost 16-10 at Batley Bulldogs on Boxing Day, included 13 new faces, a couple of them on trial, in his line-up.
The pick of them was forward Jordan Andrade, who played under Greenwood at Gloucestershire All Golds.
He scored Dewsbury’s best try – taking Paul Sykes’ smart pass – to edge the home team back in front in the second half.
Rovers, beaten 56-0 at Castleford Tigers in their opening pre-season game, featured only six players who played for them last year, including dual-registered Leeds Rhinos duo Josh Walters - who had a strong game - and Jack Ormondroyd.
The rest were trialists or new signings, plus another Leeds man Dan Waite-Pullan.
Reserve boss Paul March and conditioner Greg Stebbings were again in charge of the team, but new coach Ryan Carr is expected to arrive this week, along with Rovers’ Papua New Guinea recruits.
Featherstone had enough chances to win the game and were on top for much of the second half, though Rams did well to tough it out.
The hosts went in front after nine minutes when Sykes’ towering kick caused confusion in Rovers’ defence and Alex Brown took advantage to score.
Sykes converted the Dewsbury score and increased their lead early in the second quarter through Lucas Walshaw who went over from Robbie Ward’s short pass.
Experienced forward John Davies was suspended for the Castleford game, but gave Rovers an immediate lift when he came off the bench, as did ex-Batley pack man James Harrison. Featherstone broke their duck with a try soon after Davies’ introduction when Walters – playing in the right-centre – did well to get on the end of Morgan Punchard’s low kick five minutes before the break.
That made it 10-4 at the interval and Rovers were back on level terms 13 minutes into the second half, moments after Ward was sin-binned for alleged dangerous contact, trialist James McDaniel – from Hull University – getting over at the corner following the penalty.
Jordan Tansey converted and had a touchdown ruled out for obstruction before Andrade’s try which Sykes improved.
The former Leeds and Castleford man, who started at full-back, provided the final pass for another trialist Macauley Hallett to cross against his previous club, but Tom Halliday showed impressive pace to touch down Simon Brown’s kick to complete the scoring and ensure Rams’ place in the semi-finals.
Dewsbury Rams: Thomas, Morton, Leeming, Igbinedion, A Brown, Sykes, S Brown, Harrison, Ward, Nicholson, Walshaw, Knowles, Trout. Subs: Halliday, Ray, Halmshaw, Andrade, Mackay, Garratt, Richardson.
Featherstone Rovers: Tansey, McDaniel, Hallett, Walters, Hartley, Richardson, Punchard, Cooper, Maskill, Ormondroyd, Day, Waite-Pullan, Lockwood. Subs: Davies, Darley, Harrison, French, Beckett, Hawkins.
Referee: John McMullen (Wigan).