Oldham Athletic have dropped into the relegation zone after they were beaten by Peterborough United at the ABAX Stadium.
Junior Morais, George Cooper and Jack Marriott scored for Peterborough to condemn Latics to defeat , while George Edmundson was also sent off for the visitors. It means they have dropped to 22nd placed and are now two points from safety.
Jack Byrne and Kean Bryan both made their first starts for Latics since returning to the club earlier this week.
Oldham had a chance after just three minutes, but Peterborough goalkeeper Jonathan Bond was able to keep out Craig Davies's effort.
Johny Placide was then called into action at the other end, rushing out quickly to deny Marriott while he was through one on one.
Oldham were then forced into a change on 25 minutes, as Anthony Gerrard limped off through injury and was replaced by Edmundson.
Two opportunities then fell to Latics in quick succession, first when Ben Pringle saw a shot deflected over, and then from the resulting corner Bond kept out an attempt from Byrne.
The half then ended with Edmundson picking up his first yellow card after a late challenge on Morais, but it remained goalless at the break.
Peterborough were the better side at the start of the second half, and they soon made the breakthrough when Morais netted on 53 minutes.
The forward was allowed time on the edge of the box, and he curled the ball into the bottom corner to make it 1-0 to the home side.
Latics were forced back as Peterborough tried to double their lead, with Placide tipping Christopher Forrester's long-range effort over the crossbar, before Edmundson then cleared a shot off the line moments later.
Oldham boss Richie Wellens brought on Aaron Holloway and Dan Gardner in place of Tope Obadey and Kundai Benyu as he tried to get his side back in the game, but their task was made harder when his earlier substitute Edmundson was dismissed.
Edmundson pulled back Marriott on the half way line, with the referee showing him his second yellow card and sending the defender off.
Despite being a man light, Oldham continued to push forward, and almost levelled things up when Gardner's 25 yard strike hit the post.
Peterborough then thought they had doubled their lead when Morais had the ball in the net, but the linesman ruled it out for offside.
Their second goal of the afternoon did eventually come, with substitute Cooper finding the net just eight minutes into his Peterborough debut.
More misery was then compounded onto Oldham when Peterborough were awarded a controversial penalty on 89 minuets when Gardner was alleged to have clipped Marriott in the box. Marriott took the spot kick himself, sending Placide the wrong way to make the final score 3-0.
Oldham: Placide, Dummigan, Gerrard (Edmundson 25'), Bryan, Wilson, Fane, Benyu (Gardner 61'), Pringle, Byrne, Obadeyi (Holloway 61'), Davies
Subs not used: De La Paz, Maouche, Nepomuceno, Duffus
