MK Dons secured their seventh away victory of the season with a comprehensive victory at Leyton Orient.
Kevin Lisbie and Jamie Cureton had opportunities to put the hosts ahead, before Adam Smith's right-wing cross was met on the volley by Dean Bowditch.
Bowditch turned provider for the second goal when Smith fired past Lee Butcher from 30 yards.
Butcher then parried Dean Lewington's effort before Charlie MacDonald pounced to wrap up victory.
Leyton Orient manager Russell Slade told BBC London 94.9:
"We started off brightly against a good side and created the better chances but we didn't take those chances and we paid for that.
"It was a poor second half performance from us and we need to bounce back now. Spirit looked to be lacking in the second half and I am disappointed with that.
"There are a few hurt players in there and I hope they are because I'm hurt. Nobody likes losing, but to lose 3-0 at home is really disappointing."