A Scott Vernon header sealed victory over Sheffield Wednesday and saw Oldham seal just their second win in 14 games.
The striker grabbed his eighth goal of the season as he met Adam Griffin's pass to head home from six yards out.
Guylain Ndumbu wasted a handful of chances to put Wednesday back on level terms and was out of luck when his late effort struck the woodwork.
Oldham's Jermaine Johnson was also denied by Owls' keeper David Lucas but the home side clung on.
Oldham: Pogliacomi, Holden, Daniel Hall, Owen, Griffin, Murray,
John Sheridan, Boshell, Cooksey, Johnson, Vernon. Subs:
Westwood , Tierney, Eyres, Clegg, Roca.
Sheff Wed: Lucas, Haslam, Dean Smith, Barry-Murphy, Geary,
Mustoe, Quinn, Paul Smith, Ndumbu-Nsungu, Robins, Burchill.
Subs: Pressman, Holt, Proudlock, Shaw, Armstrong.
Referee: P Walton (Northamptonshire).