Pete Wild suffered his first defeat in caretaker charge as Macclesfield Town came from a goal down to take the three points.
Urko Vera put Latics ahead with a debut goal from the penalty spot before Harry Smith and Scott Wilson turned the game around for Macclesfield as Latics had Mohamed Maouche sent off late on.
Latics made the perfect start to the game as Callum Lang was sent running through before seeing his shot blocked by the hand of Miles Welch-Hayes in the first minute of the game.
Referee Ollie Yates pointed straight to the spot giving Vera a chance to open his Oldham Athletic account.
Vera stepped up and placed the penalty down the middle with Kieran O’Hara getting a touch with his foot, but unable to keep it out as Latics led early on.
Macclesfield tried to get themselves back in the game as Fiacre Kelleher headed wide before Michael Rose hit a volley well wide of the Latics goal.
The hosts best chance came from a mistake by Peter Clarke as his backpass was intercepted by Smith, but Daniel Iversen produced a well-timed tackle to stop the Silkmen striker.
Tyrone Marsh had a couple of tame efforts for Iversen to deal with and Latics were always looking dangerous on the counter attack.
However, Pete Wild’s men couldn’t hold onto the lead as Macclesfield equalised a minute before half time.
The ball fell to Smith on the edge of the box and he placed his shot into the bottom corner to take the teams in level at the interval.
Macclesfield took the lead nine minutes into the second half as a long punt forward from Kelleher was misjudged by Clarke with Wilson able to chip the ball over Iversen into the net.
Rose then volleyed just over the bar after Christopher Missilou had given the ball away before Lang had a shot blocked in front of the Silkmen goal.
Marsh forced a good save from Iversen as Latics were struggling to find an equaliser.
The best chance of the half for Latics came in the 89th minute as Gevaro Nepomuceno rattled the crossbar with a well taken freekick.
Maouche was then sent off for bringing down Marsh, judged to be the last man even though there were Latics players further back.
It summed up the afternoon for Latics who will have to pick themselves up for the game with Doncaster Rovers next weekend.
Attendance 3697 (1826 Away)
Macclesfield Town
O’Hara, Hodgkiss, Kelleher, Marsh, Wilson, Smith, Welch-Hayes, Evans (Cole 68’), Maycock, Rose, Cameron
Oldham Athletic
Iversen, Hamer, Clarke ©, Edmundson, Nepomuceno, Lang, Sylla (Baxter 66’), Missilou, Branger-Engone (Hunt 66’), Maouche, Vera