KYLE Kesik was sent off as the Dons slipped to a fourth consecutive defeat.
Kesik saw red, along with Oldham’s Jason Boults, for an incident spotted in a tackle with eight minutes remaining.
It came as Doncaster enjoyed their best spell of the game - finishing strongly after falling 40-14 behind but ultimately failing to get anything out of the game.
Kesik also got on the trysheet, along with Stewart Sanderson, Dean Colton, Carl Hughes and Scott Spaven, who kicked two goals.
But Tony Miller’s men struggled to handle a dominant Oldham pack and could not recover from conceding ten points in the first seven minutes of an attractive clash.
Ben Wood scored a brace of tries for the Roughyeds, Carl Forber also crossed and added seven goals, and there were further scores for John Clough, Paul Noone, Mark Brocklehurst, Ben Heaton and Boults.
Dons host Super League giants Wakefield Trinity Wildcats on Sunday (3pm) in the fourth round of the Challenge Cup.