Sheffield United could not make the most of playing against 10 men for almost half an hour and were forced to settle for a point at Boundary Park.
Oldham Athletic’s Jonathan Burn was dismissed just past the hour mark.
But despite their best endeavours Nigel Adkins’s side could not claim a winning goal.
Billy Sharp and Stefan Scougall both went close, the latter’s effort only denied by the woodwork.
But the hosts’ determination and tenacity to hold on earned them a point in spite of their numerical disadvantage.
Former Blade Danny Philliskirk had given David Dunn’s men the lead after a defensive lapse from Mike Jones’s corner before Matt Done levelled.
Adkins had changed United’s shape and personnel in an effort to force the issue following Burn’s departure.
In the first minute of stoppage time, Che Adams sent in a stinging long-range drive. But Oldham’s rearguard, despite some anxious moments, ultimately survived.
Burn was shown the red card in the 62nd minute after being booked for the second time for a foul on Sharp.
Philliskirk had headed the hosts in front after his marker was tempted away from the far post at a corner.
Jose Baxter miscued badly after United had been awarded a free-kick 10 yards outside the box.
However, Done made a perfect connection to deservedly draw United level in the 32nd minute.
Oldham: Cornell, Dummigan, James Wilson, Burn, Lafferty, Winchester, Kelly, Fulton (Brian Wilson 83),J ones (Dieng 68), Philliskirk, Poleon (Fuller 68). Unused substitutes: Coleman, Croft, Yeates, Eckersley.
Sheffield United: Howard, Freeman, Collins, McGahey, Kieran Wallace, Basham, Scougall (Campbell-Ryce 82), Adams, Baxter, Done (Sammon 63), Sharp. Unused substitutes: Coutts, Woolford, Reed, Long, Kennedy.
Referee: Kevin Wright (Cambridgeshire).