The in-form Doncaster side, who have now banked 22 points from their last eight games, took the lead through Brad Nicholson midway through the first half.
Town drew level from the penalty spot two minutes later but Rod Pursehouse quickly restored Bentley’s lead with Joe Byron adding a third before the break.
Harworth Colliery dropped to fourth after losing 7-2 at leaders FC Bolsover.
Colliery got off to a flying start with James Woodward netting inside the first 60 seconds.
Although Bolsover soon drew level Colliery’s hopes received another boost when Greg Archer converted a spot kick to make it 2-1.
The home side hit back to lead 3-2 at the break and then scored four more without reply in the second half.
Askern climbed several places after posting a 3-1 success at Bilsthorpe to claim their first league win since November 5.
Luke Williams broke the deadlock within two minutes of the restart but they had to wait until the last ten minutes before Lee Winterman added a second to give them more breathing space.
Nine-man Bilsthorpe pulled a goal back and the result remained in doubt until Tom Dobbin restored Askern’s two-goal advantage in stoppage time.
Thorne Colliery remain in the bottom three after losing by the odd goal in seven against visiting Tideswell United at Moorends.
Andrew McCreadie, Wallace Brown and Kevin Lynch netted for Thorne.