Sheffield United manager Danny Wilson was left furious after the only unbeaten record in the Football League this season was ended following a controversial penalty decision by referee Darren Sheldrake.
Shaun Williams scored the last-minute penalty for MK Dons after David McAllister allegedly brought down Angelo Balanta as they challenged for a cross from Dean Bowditch into the area.
Goalkeeper George Long guessed right but could not save the penalty and Blades captain Michael Doyle was booked for protesting before he exchanged angry words with Dons manager Karl Robinson.
Blades chief Wilson said: “I’m livid with the penalty, it’s an absolutely disgraceful decision and the referee has got it totally wrong.
“The MK Dons fans had a pop at him at the end of the first half for not giving a penalty – it was a penalty, I admit that – but that doesn’t make any difference.
“His performance in the second half was very, very poor. We have to live by it but we deserved at least a draw.”
In an even first half, Nick Blackman tested Dons goalkeeper David Martin and Ryan Lowe should have done better for the hosts from Balanta’s cross.
Blades goalkeeper Long saved well from Lowe after the interval only to be beaten at the death.
The Blades had gone into the game with a record of eight wins and eight draws but they have only scored 19 goals. They need to address that problem even though they remain second, trailing Tranmere by five points.
In fact, the Blades, who were without hamstring victim striker Dave Kitson, had made the journey south having not tasted defeat over the course of 90 minutes since Alan Smith’s winner for the Dons seven months ago.
The former Leeds United , Newcastle and Manchester United forward started on the bench but Dons possess a forward line capable of troubling the majority of back fours in the lower leagues.
They are seventh and outside the play-offs only on goal difference.
Better news for the Blades came in the shape of an England Under-21 call-up for central defender Harry Maguire ahead of the friendly against Northern Ireland.
MK Dons: Martin, Kay, Williams, Otsemobor, Gleeson, Potter,Chadwick,Balanta (Doumbe 90),Lowe (Smith 58), Lewington, Bowditch. Unused substitutes: McLoughlin, MacDonald, Chicksen, O’Shea,Sekajja.
Sheffield United: Long, McMahon (Westlake 25), Hill (McAllister 46), Maguire, Collins, Flynn, McDonald, Doyle, Williams, Blackman (Miller 74), Porter. Unused substitutes: Willis, Cresswell, Ironside, Kennedy.
Referee: D Sheldrake (Surrey).
Man of the match: Dean Bowditch.