Orient’s winless run stretched to six matches after Mark Carrington’s first-half header condemned them to defeat at stadiummk.
The Dons midfielder beat ‘keeper Jamie Jones to Aaron Wilbraham’s 31st-minute cross to head home the decisive goal.
Manager Geraint Williams dubbed the match “the poorest game of football I’ve seen all season,” and few of the O’s travelling fans will disagree.
The Dons were in control throughout, with Luke Chadwick and Dean Lewington both going close before Carrington put them in front. Chadwick was then denied by Jones following a quickly-taken free-kick.
Orient offered very little in the attacking third and that will be a worry for Williams as the season near its crucial phase.
The home side wasted several chances to extend their lead, with Mark Randall and Jermaine Easter both missing the target when they should have done better.
The win kept the Dons’ slim play-off hopes alive, but there are no such positives for O’s fans after a dour afternoon.
Williams said: “We dropped deeper and deeper instead of being brave enough to push it up the pitch.”
MK Dons: Gueret, Lewington, McCracken, Woodards, Tunnicliffe (O’Hanlon 88), Carrington, Leven, Chadwick (Morgan 84), Randall, Easter (Stirling 90), Wilbraham
Goal: Carrington 31
Orient: Jones, Purches, Chorley, Mkandawire, Demetriou, Cave-Brown, Thornton (Chambers 80), Smith, Doran (Tehoue 63), McGleish (Scowcroft 63), Jarvis
