Report: Dons 0-2 Hull City
There appeared to be an offside in the build-up to Elmohamady’s 19th minute strike, which came after Karl Robinson's men had started brightly.
The Dons pushed hard for a leveller but it wasn't to be, and the visitors wrapped up the victory with almost the last kick when Diame curled home from 18 yards on the break.
Darren Potter, Dean Bowditch and Carl Baker returned to the starting line-up in place of Rob Hall and Ben Reeves, both injured, and Jake Forster-Caskey, who has gone back to parent club Brighton & Hove Albion.
After comfortably handling some early Hull pressure, the Dons began to impose themselves on their opponents with their flowing football as the clocked ticked towards the 15-minute mark.
Potter’s return was clearly having a positive impact on the men from MK1, who were enjoying the majority of the possession in Hull’s half.
But, against the run of play, a hopeful ball across the box from Abel Hernandez was turned home from close range on 19 minutes by Ahmed Elmohamady, who looked suspiciously offside at the back post.
Nice interchange between Hernandez and Chuba Akpom created a chance for the latter shortly afterwards but David Martin did well to get down and deny the Arsenal loanee.
The Dons responded well though and a Jordan Spence cross only just evaded his team-mates in the box including Josh Murphy, who then saw a dangerous delivery from the other side brilliantly cleared away.
A Baker shot was deflected into the grateful arms of Allan McGregor and Murphy drove over in consecutive minutes as the Dons continued to push for an equaliser.
Simon Church forced McGregor into a smart save from the edge of the box after good play in the middle of the park by firstly Diego Poyet and then Baker.
Elmohamady almost made it 2-0 on the stroke of half-time but, after beating the offside trap and rounding Martin, he scooped his effort over the top with an empty goal to aim at.
The second half started much like the first half with the game being evenly contested and defences on top.
As the game past the hour mark, it was on a knife-edge as Hull looked for a second and the Dons looked for a way back into it, but chances were at a premium.
Karl Robinson introduced Daniel Powell and Nicky Maynard for Bowditch and Church with 25 minutes remaining as the Dons’ boss aimed to freshen up his side’s attacking threat.
That helped lift the Dons, who were getting into some fantastic areas but couldn’t quite find the killer ball to create real goalscoring chances.
Baker continued to threaten and, after cutting inside and out his man, his cross for the lively Maynard was cleared away – the Hull defence were getting busier.
Alex Bruce, son of Hull’s manager Steve, was in the right place at the right time to deal with Powell’s teasing cross from the left on 75 minutes – Antony Kay headed over the resulting corner.
Powell saw a drive deflected behind for a corner after nice build-up play including Maynard before Murphy fired wide from 20 yards.
Despite their dominance, the Dons were caught on the counter in the final minute and Mo Diame curled home from the edge of the area to wrap up a victory for the visitors.
MK Dons: Martin, Spence, McFadzean, Kay, Lewington (c); Potter (Carruthers 82), Poyet; Baker, Bowditch (Powell 66), Murphy; Church (Maynard 66).
Unused subs: Cropper, Hodson, Rasulo, Gallagher.
Bookings: McFadzean, Potter, Lewington.
Attendance: 15,360 (2,907 Hull City fans).
Referee: Graham Scott