Doubles from Danielle Carter and Natalia Pablos and a classy goal from Kelly Smith ensured Arsenal kept their chances of Champions League football alive.
But the defeat left point-less Doncaster nine points adrift of safety with just four games remaining.
Carter’s good movement saw her slide the ball home unmarked from Emma Mitchell’s cross less than 15 minutes into the match.
Arsenal looked sluggish at times but clinched the second shortly after Natalia and Smith were introduced, the former heading home Alex Scott’s cross with just over 20 minutes remaining.
Belles were determined to go down fighting and created half chances but were once again hit on the counter as Natalia grabbed her second from the bench with just five minutes remaining. A Jordan Nobbs through ball found the Spaniard who just managed to get the ball under Nicola Hobbs to seal the three points.
Carter grabbed a second of her own soon after as Belles tired, the England international smashing home Chloe Kelly’s low cross before Smith finished the night off in style.
The veteran forward picked up the ball 30 yards from goal and promptly sent the ball floating over Hobbs into the net for one of the goals of the season.