Relegation-threatened Oldham Athletic lead MK Dons at half time through Adam Lockwood's strike.
The first chance of the game fell to the hosts when Ben Reeves put a teasing cross into the box, but none of his teammates could get on the end of it.
Izale McLeod also came close to opening the scoring for the Dons after Samir Carruthers picked him out in the box, but the striker couldn't get his header on target.
McLeod was involved again moments later, playing the ball to Luke Chadwick who in turn found Carruthers, but the loanee couldn't make room for the shot and the chance went begging.
Oldham grew into the contest, and Jon Stead nearly put the away side in the lead after rounding David Martin, only for his effort to be cleared off the line.
Buoyed by their chance, Oldham pushed forward once more and broke the deadlock through Lockwood, who headed home from close range.