Match ends, MK Dons 0, Peterborough United 2.
Britt Assombalonga scored twice to beat MK Dons and strengthen Peterborough United's League One play-off prospects.
Dons keeper David Martin saved from Assombalonga and Nicky Ajose, with Sanmi Odelusi testing Bobby Olejnik at the other end in a goalless first half.
After the break, Assombalonga tucked in Michael Bostwick's cross and then converted from the spot after George Baldock fouled Conor Washington.
The brace takes the former Watford striker's tally to 27 for the season.
The home side, who could only name six substitutes, were looking for a third consecutive win to put pressure on sixth-placed Posh, but Olejnik's save from Dean Lewington's effort was as close as they came to a late rally.
Instead, Darren Ferguson's men pulled six points clear of MK with a game in hand.
MK Dons boss Karl Robinson told BBC Three Counties Radio:
"We understand how difficult it was going to be today, but there was very few opportunities in the first half.
"(On the penalty) I've seen a frame by frame. It's definitely not a penalty.
"We've been beaten, we've got to accept that. They'll be a lot of people, including myself, who will be very disappointed leaving today.
"I don't think the players attitude can be questioned today. I thought everyone put a right effort in, and so did the fans."
- 18BaldockBooked at 60mins
- 3LewingtonBooked at 29mins
- 7GleesonBooked at 30mins
- 23SpenceBooked at 55mins
- 21HallSubstituted forRasuloat 77'minutes
- 14AlliBooked at 84mins
- 13McLeodBooked at 82mins
- 11SmithSubstituted forChadwickat 62'minutes
- 27OdelusiSubstituted forBowditchat 63'minutes
- 2AlcockBooked at 19mins
- 22NugentBooked at 66mins
- 14RoweBooked at 82mins
- 24WashingtonSubstituted forIsgroveat 87'minutes
- Keith Hill
- Shots on Target
Second Half ends, MK Dons 0, Peterborough United 2.
Attempt missed. Dean Bowditch (MK Dons) right footed shot from outside the box misses to the left.
Hand ball by Britt Assombalonga (Peterborough United).
Corner, MK Dons. Conceded by Ben Nugent.
Attempt blocked. Dean Lewington (MK Dons) right footed shot from outside the box is blocked.
Attempt saved. Dean Lewington (MK Dons) left footed shot from a difficult angle on the left is saved in the bottom left corner.
Substitution, Peterborough United. Lloyd Isgrove replaces Conor Washington.
Attempt missed. Luke Chadwick (MK Dons) right footed shot from outside the box is just a bit too high.
Attempt saved. Giorgio Rasulo (MK Dons) header from the centre of the box is saved in the top centre of the goal.
Corner, MK Dons. Conceded by Michael Bostwick.
Bamidele Alli (MK Dons) is shown the yellow card.
Bamidele Alli (MK Dons) has gone down, but that's a dive.
Corner, MK Dons. Conceded by Robert Olejnik.
Izale McLeod (MK Dons) is shown the yellow card.
Tommy Rowe (Peterborough United) is shown the yellow card.
Izale McLeod (MK Dons) wins a free kick on the left wing.
Foul by Jack Baldwin (Peterborough United).
Dean Lewington (MK Dons) wins a free kick on the right wing.
Foul by Josh McQuoid (Peterborough United).