Latics were unable to build on their three-match winning run and fell to a 2-0 loss to Scunthorpe United.
Second-half strikes from Jacob Bedeau and Kevin Van Veen secured all three points for Neil Cox’s men.
Latics’ first sight of goal came from a free kick in the fourth minute with Danny Rowe’s characteristic powerful drive evading a telling touch and going narrowly wide of the far post.
Exciting winger Dylan Bahamboula showed his first sign of the attacking flair that he possesses in the 16th minute when he jinked his way past two Scunthorpe defenders, giving him a sight at goal, but his effort was turned behind by Matt Howard.
Rowe showed that he can be useful in both boxes and he kept the scores level with a brilliant clearance off the line, denying Manny Onariase.
Harry Clarke had a half chance to give Oldham the lead when he gets on the end of Davis Keillor-Dunn corner, but his header went wide of the mark and the Iron had a chance of their own moments later, Abo Eisa forcing a smart save from Ian Lawlor.
Kevin Van Veen had a long-range effort that went narrowly wide in the 32nd minute and the Dutchmen tried his luck again just moments later, curling a free kick over the bar from a tight angle.
Scunthorpe continued to enjoy a good spell in the game and Ryan Loft would have opened the scoring with a spectacular overhead kick if it wasn’t for a good stop from the Latics keeper.
The Iron finished the half strongly and would have been disappointed to go in with the scores still level.
Oldham did come out stronger after the interval and Bahamboula had some joy down the left-hand side and continued to get past defenders with ease. His direct play gave him a chance to get the ball into the box but Garrity’s header was wide.
It was down the left side again where Latics’ next chance came from. Bahamboula and Keillor-Dunn combined well before the latter whipped in a cross that Garrity could only direct into the arms of Howard.
At the other end, Van Veen found himself with a bit of space in the Latics box but a great tackle from Tom Hamer meant he didn’t get a shot on goal.
Oldham failed to clear the resulting corner and Bedeau beat the offside trip before sliding his effort underneath the oncoming Lawlor to give Scunthorpe the lead on the hour mark.
In Latics search for an equaliser, Rowe had a chance, but his strike hit a fellow Oldham player on its way out for a goal kick.
Van Veen ensured his side took maximum points as he marked his return to League Two action with a goal from range. The Dutch striker had far too much room through the middle and gave Lawlor no chance with his powerful strike.
Harry Kewell’s side were unable to mount any serious pressure and the visitors were able to see the game out and secure three valuable points, making it their first away win since New Year's Day which was back at Boundary Park by the same scoreline.
Oldham Athletic XI – Lawlor (GK), H.Clarke, Borthwick-Jackson, Jameson, Hamer © (Grant,75) , Ntambwe, Garrity, Blackwood (62, Fage), Keillor-Dunn, Bahamboula, D.Rowe
Subs – Bilboe (GK), Jombati, Piergianni, Whelan, Grant, Fage, Barnett
Scunthorpe United XI – Howard (GK), J.Clarke (J.Rowe, 90), Bedeau, Onariase, Gilliead ©, Loft, Van Veen (McAtee, 81), Eisa (Hippolyte, 87), Brown, Spence, Beestin
Subs – Watson (GK), Green, Hippolyte, Hallam, Olomola, J.Rowe, McAtee
Goals –Bedeau (60), Van Veen (78)
Referee: Lee Swabey