Scott Fraser struck the winning penalty just after half-time to secure a 2-1 win for MK Dons at Sunderland.
The Black Cats threw away an early lead and ultimately the points to suffer defeat for only the second time this season in League One.
But MK Dons will not care about that after extending their own unbeaten run to four matches to climb up the table – ending a 20-game run without a win away from home.
MK Dons looked confident from the start, even though Sunderland took the lead in the 12th minute when Max Power hammered home from the edge of the area.
The lead lasted less than four minutes because Ben Gladwin’s delivery from the left was flicked inside the far post by the head of experienced striker Cameron Jerome.
Sunderland did not create enough clear-cut chances and immediately after the restart Power gifted MK Dons a second by bringing down Fraser in the area. Fraser sent Remi Matthews the wrong way from the spot.
Sunderland had chances. Will Grigg wasted one when he somehow could not convert Lynden Gooch’s low cross.
Denver Hume was denied by Andrew Fisher a couple of times late on, while Matthews spared Sunderland further frustration when he saved from Fraser.