Karl Robinson’s controlled the game from start to finish and went close on a number of occasions, including hitting the woodwork twice, but they couldn’t make their dominance count in front of goal.
The only goal came in the first half when Alex Jones scored at the second attempt after his penalty had been saved by David Martin.
GB Williams, Ed Upson and Dean Bowditch returned to the starting XI as there were three changes from the Dons’ last league outing – a 2-0 win at Oldham Athletic.
The Dons men started firmly on the front foot and looked very positive as they took the game to the Valiants.
It wasn’t long before the men from MK1 had created a good chance, Kieran Agard forcing Jak Alnwick into a smart save from a Samir Carruthers cross on six minutes.
Ryan Colclough, playing against the side he watched as a boy, then sent a shot over the bar before the in-form Agard saw an effort deflected wide after making some room for himself.
The Dons maintained their dominance and Dean Bowditch fired over before the impressive Carruthers couldn’t quite find a team-mate with a dangerous ball into the box.
Port Vale’s only effort in the opening 30 minutes came courtesy of a 25-yard free-kick which was blasted over by Sam Hart - the Dons defence were looking as impressive as the forwards.
The men from MK1 came very close to taking a deserved lead on 32 minutes but Dean Lewington’s low drive from 15 yards hit the post – another let-off for the visitors.
Completely against the run of play, Bruno Ribiero’s side were given a golden opportunity to take the lead when Lewington handled in the box. David Martin saved Alex Jones’ penalty but the striker turned home at the second attempt to hand the visitors a surprise advantage.
That gave Vale something to hold on to and they did improve, however, the Dons remained on top and Joe Walsh headed off target from a corner two minutes into the second half.
Carruthers then shot straight down the throat of Alnwick from 25 yards before a superb bit of from Bowditch set up a shooting chance for himself but it was saved at a tight angle.
Ben Reeves was introduced just before the hour mark and he picked out Lewington, who headed wide from the former’s corner.
Carruthers delivered a dangerous ball midway through the second half after a smart interchange with Agard but it was slightly too far in front of Bowditch at the back post.
Nicky Maynard came on for centre-back Paul Downing as Robinson made a very offensive change to try and find a way back into the game.
First substitute, Reeves, dragged a shot narrowly wide on 73 minutes from 20 yards while, at the other end, Martin brilliantly denied Jones on a rare foray forward for Vale.
With the game entering the final 10 minutes, Colclough got into the box and pulled the ball back but couldn’t pick out a team-mate as another opportunity went begging.
The busy Maynard and fellow substitute Brandon Thomas-Asante both forced saves from Alnwick late on and Reeves hit the bar with an almost-perfect free-kick as the Dons continued to push for an equaliser until the whistle, but it wasn’t to be.
Starting XI: Martin; GB Williams, Downing (Maynard 69), Walsh, Lewington (c); Potter, Upson (Reeves 59), Carruthers; Bowditch, Colclough (Thomas-Asante 84), Agard.
Unused subs: Nicholls, Hendry, Powell, Tshimanga.
Bookings: Upson, Lewington, Potter.
Attendance: 8,259 (292 Port Vale fans).