Relegation remains a worry for Orient after their 2-0 defeat at Boundary Park on Tuesday night extended their winless run to seven games.
Goals from Deane Smalley and Dale Stephens meant Oldham had the game wrapped up shortly after half-time.
Smalley slotted home after exchanging passes with Pawel Abbott after 20 minutes, before Stephens made the game safe by scoring from 12 yards four minutes after the restart.
Oldham looked dangerous on the break, with Daniel Nardiello and Abbott both coming close to making things even more embarrassing for the O’s.
Chris Taylor was a constant threat throughout, shooting just wide after cutting inside from the left and laying on the crucial pass from which Stephens wrapped the game up for the Latics.
Orient lacked any cutting edge in attack, with Jonathan Tehoue wasting their best chance when he headed a 19th-minute corner wide. Oldham were able to comfortably see out the match and Orient can have few complaints over the final scoreline.
There was some good news for O’s fans in the aftermath of this latest defeat, with news that Jonathan Tehoue had signed a new two-and-a-half year contract at Brisbane Road.
Manager Geraint Williams said: “We’re delighted to sign Jonathan on a longer-term contract.
“He has done well since he came to the club, his form has improved as his fitness has returned and we hope that continues now.”
Oldham: Brill, Jacobson, Hazell, Gregan, Whitaker, Taylor (Worthington 88), Lee, Stephens, Smalley, Abbott (Eaves 86), Nardiello (Colbeck 58)
Goals: Smalley 20, Stephens 49
Orient: Jones, Purches, Mkandawire, Ashworth, Demetriou (McGleish 79), Chambers, Daniels, Smith, Doran (Baker 61), Tehoue (Jarvis 74), Scrowcroft
