MK Dons picked off out-of-sorts Walsall to claim victory and heap more pressure on under-fire home boss Mat Sadler.
Rushian Hepburn-Murphy finished off a slick move emanating from Priestley Farquharson's risky pass on the half-hour.
The Saddlers improved after being booed off at half-time, but Paul Warne's promotion hunters withstood pressure to seal a sixth win in eight unbeaten Sky League Two outings through Jon Mellish's finish four minutes from time.
Farquharson's error gifted Mellish the ball, with Alex Gilbey setting up Hepburn-Murphy to calmly curl the opener inside the far post.
Injured referee Peter Wright was replaced by fourth official Dean Watson, but there was no change to the pattern of the game with Kacper Lopata blocking Hepburn-Murphy's point-blank shot late in the first half.
Walsall showed far more energy after the break, with Daniel Kanu's 57th-minute effort needing a strong right hand from Craig MacGillivray at his near post.
Courtney Clarke thumped over a 25-yard drive and Kanu drew another save from MacGillivray, but Mellish secured the points when he thumped in the rebound from Scott Hogan's blocked effort.
Report supplied by PA Media.