MK Dons suffered successive league defeats for the first time since January 2008 as Oldham ended their unbeaten away record at Boundary Park.
Well-struck goals from Alan Sheehan and Keigan Parker sent the Dons to a first away defeat of the season, despite Latics goalkeeper Dean Brill handing them a lifeline with a late own-goal. It was to be a disappointing night for the men from MK, who also saw boss Paul Ince sent to the stands following a disagreement with referee Tony Bates, as they failed to build on a promising performance against leaders Leeds at the weekend.
On what was always likely to be a tricky night in Greater Manchester against an Oldham side showing signs of life after a poor start to the campaign, Ince made attacking changes to his side - setting aside his preferred 4-2-3-1 formation in favour of a more orthodox 4-4-2. Aaron Wilbraham and Jabo Ibehre were chosen to lead the line in Jermaine Easter's ongoing absence, while Peter Leven stepped into a creative midfield role in place of the suspended Jason Puncheon.
It was a decision that almost paid off immediately when Ibehre combined well with Luke Chadwick down the left to send the winger into space, but Wilbraham was unable to convert his cross from a central position.
Typically enough, Oldham took the lead with their very next attack through Sheehan - the on-loan Leeds man who has haunted the Dons before. Back in March, it was Sheehan, then on loan at Crewe, who won a late penalty at stadiummk to snatch two crucial points from the promotion-chasing Dons - two points that would have seen them promoted automatically at the end of the season. In the grand scheme of things, his 25-yard strike through a crowd of bodies and past an unsighted Willy Gueret might not prove quite as pivotal in the Dons' season. But in the context of this game, it was huge. The visitors were knocked out of their stride and, with Blackburn loanee Alex Marrow providing some real drive from midfield, Oldham were well on top.
Marrow just failed to make decisive connection with Sheehan's free-kick on 15 minutes and wasn't a million miles away from Keigan Parker's centre shortly afterwards. Dons were not without threat - Wilbraham marginally off target with a header from Chadwick's cross and Mathias Doumbe finding Stephen Gleeson in behind only for the cutback to go unconverted - but they were far from their dominant best and they had their goalkeeper to thank that they were not further behind by the break.
Having been handed a reprieve by Marrow on the half-hour when the Latics midfield sent a wayward clearance straight back into his hands, Gueret showed his true quality with a super stop just before half-time - diving to his right instinctively to keep the ball out after another Sheehan free-kick had cannoned off the heels of Reuben Hazell.
With three Dons players booked in the first half - including Luke Howell for what looked a brilliant challenge on Chris Taylor in front of the dugouts - Ince was quick to confront Referee Bates at the half-time whistle and was ordered to the stands as a result. Ince's team did begin to improve after the break and Ibehre twice went close within 10 minutes - first firing over from Leven's pass and then straight at Brill after driving past Sean Gregan.
Oldham looked quite happy to play on the break though and the Dons were once again grateful to Gueret when the Frenchman slid out superbly at the feet of Danny Whittaker just before the hour. The impressive Pawel Abbott had a goal chalked off for offside after being found by Taylor inside the box, but the home fans didn't have to wait long for a second goal.
With the Dons pressing forward and mounting their best spell of pressure in the game with 20 minutes to go, Oldham broke to devastating effect. Abbott held up Gregan's clearance on halfway before sending Whittaker sprinting down the left. His early ball across the box found Parker in space, who stepped inside David McCracken and finished superbly with the outside of his right foot from 16 yards. Dean Morgan was brought on for his Dons debut as Ince's side desperately sought a route back into the game and the former Luton man nearly provided it when he shot just wide from Gleeson's centre.
And from another Gleeson cross with 10 minutes left, Wilbraham's knock-down just evaded the lurking Ibehre in the six-yard box. Abbott was foiled brilliantly by Gueret as Oldham threatened to rub salt into the Dons wounds, but instead they were forced into a tense rearguard when substitute Richie Partridge's cross smacked the far post and crawled over the line via Brill. Wilbraham looped a hopeful header just wide and even Gueret advanced for the final corner of the night, but Oldham would hold on for a third straight win.
A frustrating night for the Dons, but they must recover quickly with a testing trip to Brighton on the horizon.
Oldham Athletic (4-4-2): Brill; Lomax, Hazell, Gregan (c), Sheehan; Whittaker, Marrow, Furman, Taylor; Parker (Lee 88), Abbott (Brooke 90+3).
Subs not used: Black, Ollerenshaw, Rowney, Colbeck, Bembo-Leta.
Goals: Sheehan 8, Parker 70.
MK Dons (4-4-2): Gueret; Doumbe, Powell (Morgan 73), McCracken, Lewington (c); Gleeson, Howell (Partridge 63), Leven, Chadwick (Johnson 36); Ibehre, Wilbraham.
Subs not used: Searle, Carrington, Davis, Swailes.
Goals: Brill (og) 85
Booked: Lewington, Doumbe, Howell, Leven, Johnson.
Attendance: 3,630 (180 away)
Referee: Tony Bates (Staffordshire)