For the second week running there was late heartache for Latics as they were denied what would have been a hard-fought point in stoppage time at Swindon.
Seven days after surrendering a lead to lose against Carlisle, there was acute disappointment once more, Dion Conroy converting a header at the far post to consign John Sheridan’s side to defeat.
It completed a calamitous period of added time for Latics, who minutes earlier had Jordan Clarke sent off for a second yellow card.
Although Oldham had to fend off heavy pressure from their play-off chasing opponents as the game progressed, the visitors would have been worth a share of the spoils having put their bodies on the line throughout the second period.
To that end, no-one summed up the Latics character more than Carl Piergianni but ultimately his efforts were in vain.
What’s more, with two glorious chances inside the opening thee minutes, Oldham should have found themselves in front but as it was those chances were to ultimately prove costly.
Sheridan named an unchanged line-up from the team that lost against Carlisle and there was good intent from the visitors early on.
Piergianni was unable to direct a header past goalkeeper Jojo Wollacott having read the flight of the ball from Nicky Adams after a free-kick from Clarke.
And within 60 seconds, Dylan Bahamboula was unable to make the most of the space afforded to him on the edge of the area, shooting over after the ball had sat up invitingly.
Further chances would follow, Christopher Missilou narrowly clearing the crossbar from similar range after good play from Bahamboula in releasing Sam Hart to supply the pass.
Bahamboula was heavily involved in the early stages, teeing up David Keillor-Dunn, whose effort was held by Wollacott but the home side then started to show more authority.
Piergianni was required to make the first of several last-ditch blocks to deny Ricky Aguiar, who was also denied by Danny Rogers.
Bahamboula also led the Oldham charge at the start of the second period, shooting over from 30 yards after latching onto a loose ball before displaying excellent footwork as he broke into the area, electing to square to Adams rather than shoot but he was unable to find the pass.
Yet as the second half wore on, Latics found themselves increasingly on the back foot. Ellis Iandolo shot over and substitute Jonny Williams sent an effort into the side-netting.
Hart produced a last-ditch challenge to deny Louis Reed before a brilliant reaction save from Rogers kept out Williams but there was nothing he could do to prevent Conroy in stoppage time.
Oldham Athletic: Rogers, Clark, Hart, McGahey (Fage 46), Piergianni, Adams, Whelan, Hope (Stobbs 87), Keillor-Dunn, Bahamboula, Missilou.
Subs not used: Leutwiler, Hunt, Hopcutt, Couto, Vaughan.
Swindon Town: Wollacott, Odimayo (Parsons 83), Iandolo, Conroy, Davison, Payne (Williams 68), O’Brien, Mitchell-Lawson (Egbo 77), Hunt, Reed, Aguiar.
Subs not used: Baudry, Ward, East, Minturn.
Referee: David Rock
Attendance: 11,390 (280 away).