Andy Bishop scored his seventh and eighth goals of the season as Bury earned a valuable victory at Oldham.
It started badly for Oldham, who had keeper Alex Cisak sent off after just 10 minutes for bringing down Bishop as the striker burst clear on goal.
Cisak's replacement - 38-year-old goalkeeping coach Paul Gerrard - saved the weak resulting penalty from Bishop.
Bishop made amends by first volleying home from six yards before his close-range header sealed the victory.
The visitors were also reduced to 10 men in injury time when Lenell John-Lewis received his second yellow card.
VIEWS FROM THE DRESSING ROOM
Oldham Athletic manager Paul Dickov told BBC Radio Manchester:
"I'm delighted and proud of the effort the 10 men put in for 79 minutes.
"It was a sending off. Alex has been fantastic for us but his starting position has to be better there and you're up against it.
"We've lost 2-0 against one of our local rivals but I'm proud of my players, which doesn't feel right."
Bury manager Richie Barker told BBC Radio Manchester:
"I thought in terms of our performance, the second half was nowhere near good enough.
"But after saying that at 2.55 would we have taken a 2-0 win over Oldham? Of course we would.
"I think Bish (Andy Bishop) has learnt to adapt his game and I'm sure he's a cleverer striker than he was three or four years ago."