Ben Reeves struck in stoppage time as MK Dons snatched victory against 10-man Oldham to renew their play-off hopes.
Oldham took the lead when Gary Harkins' cross was flicked in by Adam Lockwood.
Samir Carruthers equalised after riding three challenges before finishing into the bottom corner.
The Latics were reduced to 10 men when Genseric Kusunga was shown a second yellow card and they could not hold on as Mark Oxley found Reeves who tapped into an empty net.
Meanwhile, Oldham have released winger Sidney Schmeltz after his loan spell with Shrewsbury Town was terminated on Friday.
VIEWS FROM THE DRESSING ROOM
Milton Keynes Dons manager manager Karl Robinson told BBC Three Counties Radio:
Karl Robinson: MK Dons boss on Oldham win
"I thought Oldham were very good first half, or we were very poor. But I think sometimes it's important to look how good they were. They really caused us an awful lot of problems.
"The refereeing decision for their first goal was diabolical. I've not seen a decision like that. I got told Reevesie pushed him. I said 'Well how can someone push somebody if they're in front of them?
"I thought second half I thought we were very good. Our gameplan was good and we stuck to what we wanted to do for the first half. I thought we had a bit more dominance and passion.
"I had a bit of a go at Samir at half-time, he was poor for his standard that he set at the start of the season. I also said if you want to be a good player then you've got to score goals, and he shoved one right up me there. He said take that one!"
Oldham manager Lee Johnson told BBC Radio Manchester:
Post-match: Oldham manager Lee Johnson
"It's very disappointing, a bit of a gut-wrencher because I didn't feel we deserved it.
"We played very well, six or seven of the lads, I thought, were superb. A couple of players let us down on the day.
"He [Genseric Kusunga, after getting sent off] has let down the team today.
"You expect a player who's played in the Champions League to be a bit cleverer and not dive in for a rash tackle."
