MK Dons lost for the first time this pre-season as they were out-played by Northampton Town at the PTS Academy Stadium on Friday night.
Goals in either half from Sam Hoskins and Harry Smith put Keith Curle's side in control, but it should have been more had Smith and Andy Williams found the target later on.
Kieran Agard tapped home Ben Reeves' cross with four minutes ago to dampen the blow.
Paul Tisdale named a half-and-half team to start the game – the back six had a realistic chance of lining up together against Bury for the opening day of the season, while most of the forward five is likely to play a bit-part.
Coming up against EFL opposition for the first time this summer, Dons made a sluggish start and found themselves trailing after 13 minutes. A lapse in concentration from Conor McGrandles allowed Sam Warburton to nick the ball from him, feeding Sam Hoskins on the Cobblers' left to fire past Lee Nicholls.
The goal livened Dons up somewhat, but the performance didn't much improve. Joe Mason and Jordan Bowery both saw headers flash wide, while Ryan Harley fizzed one high and wide after manufacturing himself some space in the centre of the park.
While Northampton's chances began to dry up and the half wore on, Warburton still had the best chance to score again, but Nicholls was a match to his strike.
Dons should have been level eight minutes into the second half, but Joe Walsh showed all the finishing of a centre half when he blasted Mason's excellent pull-back well over David Cornell's bar.
And the home side would make them pay when Harry Smith, who a few minutes earlier had similarly fired well over the bar, rose highest to nod home Nicky Adams' corner.
Smith had a great chance to wrap up the result five minutes later when Adams once again teed him up, the striker dragged his strike wide though.
Tisdale's changes did little to alter the course of the game, with Andy Williams twice coming close to a third for Cobblers, while Dons struggled to create, though Agard managed to net a consolation with four minutes to go.
Attendance: 1,904 (596)
MK Dons: Nicholls, Williams, Lewington (Cargill 78), Walsh, Martin, Brittain, Houghton (Poole 77) Harley (Boateng 61), McGrandles (Reeves 74), Bowery (Agard 61), Mason (Asonganyi 74)
Subs not used: Moore, Nombe, Kasumu, Pattison, Sorinola,