Goals from former Spireites Kane Drummond and Mike Fondop did the damage in the first-half, with the dominant visitors deservedly in front.
The Blues made a triple change at the break but Drummond grabbed his second goal and Oldham’s third with less than 20 minutes remaining, which was the cue for many home fans to head for the exits.
Here are our player ratings from the game...
5. Dylan Duffy 4
Dylan Duffy 4 Handed a start at left-back and he struggled. He was caused some problems by Drummond early on and midway through the half he got caught under Stevens' cross which left Drummond unmarked at the back post and he applied the finish. Looked to lose confidence after that and looked nervous. Off at the break. Photo: Submitted
6. Sammy Braybrooke 5
Sammy Braybrooke 5 Got his side out of jail once or twice but wasn't able to dictate play like normal. Photo: Tina Jenner
7. Tom Naylor 4
Tom Naylor 4 Not really in the game. Just couldn't influence it like he did on Saturday. Played higher up after the break but had no joy. Photo: Tina Jenner
8. Dilan Markanday 5
Dilan Markanday 5 Looked the more likely out of anyone to make something happen but his influence was still limited. Photo: Tina Jenner