Pawel Abbott scored the only goal of the game as Oldham beat fellow strugglers Tranmere to move out of the relegation zone.
The former Huddersfield striker struck just before half-time to secure three precious points for the Latics and keep Rovers in the bottom four.
Jason Price spurned an early chance for the visitors before Aaron Cresswell missed an early opportunity for the home side.
Latics midfielder Dean Furman saw a deflected shot well saved by Luke Daniels before Rovers striker Ian Thomas-Moore fired just wide.
But the clinical Abbott was on hand to head Oldham in front after an inviting cross from Dale Stephens in the 41st minute.
Paul McLaren blazed over and Cresswell missed the target with a free-kick before Latics keeper Dean Brill made two fine saves late on to deny the home side.