Peterborough United were second best all over the pitch in the first half at stadium: mk and were fortunate to just be three goals down at the interval as Milton Keynes Dons eased to a comfortable victory and despite an improved showing in the second period, Darren Ferguson's men never looked likely of getting back into proceedings.
Posh made a disastrous start to proceedings, falling behind inside the opening five minutes as Powell got past Bostwick in a wide area and squared for GRIGG for had a simple task of sweeping the ball past Alnwick.
Erhun Oztumer saw a shot blocked after robbing Potter of possession in a wide area. The Turkish Messi went closer to levelling the scores on 24 minutes as his stunning left-foot shot crashed against the top of the crossbar after cutting inside from the left.
Powell wasted a presentable chance on 28 minutes, but his air kick allowed Posh to clear.
The Dons made it 2-0 just after the half hour as more poor defending allowed the hosts to take advantage. A short corner was easily worked and REEVES let fly on his left-foot and drilled the ball past a statuesque Alnwick at his near post.
Darren Ferguson made two changes on 35 minutes with Oztumer and Smith replaced by Maddison and Brisley. Powell fired into the side netting after wriggling past two poor challenges.
Baker dragged a shot wide of the target on the stroke of half-time as Posh desperately tried to inch their way to half-time without conceding again.
A minute into stoppage time, the Dons made it 3-0 as REEVES cut inside and curled a shot past Alnwick and into the back of the net.
Norris side-footed inches past the post on 49 minutes after a good run and cross from Marcus Maddison down the right hand side.
Maddison had a presentable chance moments later as James robbed Potter, but after advancing onto his left-foot, he blazed over.
Washington replaced Norris on 55 minutes and he threaded the ball to Maddison on the left, but his shot was straight at McLoughlin.
James saw a back header from a Taylor corner kick cleared off the line before Maddison saw a shot blocked. Ntlhe sliced a shot wide of the target after a good patient build-up from Posh who were certainly playing better in the second period.
Posh appealed in vain for a penalty kick as Taylor's cross appeared to strike an arm on 72 minutes but the referee awarded just a corner kick.
Alnwick denied Grigg after his initial clearance had put Posh in all sorts of panic at the back. Brisley cleared off the line from substitute Williams on 82 minutes. Substitute Cole saw a shot deflect wide for a corner before Alnwick denied Williams by his near post.
Full-time: Milton Keynes Dons 3-0 Peterborough United
MK Dons: McLoughlin, Lewington, McFadzean, Kay, Potter, Reeves (sub Williams 69min), Grigg, Baker, Spence, Powell (sub Cole 83min), Carruthers (sub Andrews 78min). Unused subs: Burns, Hodson, Green, Hitchcock, Andrews.
Posh: Alnwick, Smith (sub Brisley 35min), Ntlhe, Bostwick, Taylor, Payne, James, Oztumer (sub Maddison 35min), Burgess, Norris (sub Washington 55min), Beautyman. Unused subs: Henry, Zakuani, Mclean, H. Anderson.
Attendance: 11,162 (1,798 Posh fans).