Grigg’s opener on 68 minutes came three minutes after Glovers defender Ben Nugent was sent off after receiving a second yellow. Nugent had already been harshly booked after a handball in the first half and after his dismissal, the Dons pressed home their numerical advantage with Powell slotting home with six minutes left.
Yeovil drop to nineteenth position in the League One table with their visitors remaining in fourth spot.
After last Saturday’s 2-0 defeat at Crawley, boss Gary Johnson rang the changes making four alterations to his starting lineup. Out went the injured Kieffer Moore along with Joel Grant and Jack Price from midfield and defender Jakub Sokolik. In their place came new Manchester City loan youngster Jordy Hiwula up front with central midfielders James Berrett and Simon Gillett and Ben Nugent in central defence.
The first half was a mediocre watch with both sides struggling to cope with a swirly wind and chances were at a minimum. Daniel Powell was in the thick of the action, blazing over after a good run and then becoming the first of nine players booked by card-happy ref Carl Berry for clattering into Joe Edwards.
Yeovil livened up halfway through the half and had two clear chances to open the scoring. James Hayter fired just wide after finding himself in space outside the box and the veteran striker then set up Hiwula who nodded narrowly wide back across the keeper.
And that was really it before the break in terms of action. Nugent was booked on 44 minutes for handball when it looked more like he’d been fouled by Grigg but Ben Reeves free kick curled wide of the far post.
The second half started far more brightly with both sides creating a pair of chances apiece in the first five minutes. Yeovil broke through Gillett who fed Hiwula but the striker shot way over the crossbar and after Gillett’s next effort was blocked, Hayter’s follow up was brilliantly saved by David Martin, the big keeper stretching out a foot to deny the Yeovil forward.
Back came the Dons and Grigg’s shot skimmed the top of the bar but ref Berry ruled that Jake Kean had tipped it over. From the resulting corner, Benik Afobe’s bicycle kick went over too.
On 65 minutes, the game changed for the worse for the hosts and ultimately cost them the match. Nugent, already booked in the first half, brought down Grigg in full flow and the official had no alternative to show a second yellow and subsequent red. The first yellow was costly, the second was correct.
Three minutes later, the deadlock was broken when Grigg raced on to a through ball, controlled and fired low into the corner for his sixth goal in eleven games.
The game then entered a niggly phase with seemingly every challenge from either side ending in a piffling yellow card from the official; Powell and Randall (MK Dons) and Ralph & Hiwula for the home side all having their names taken by the referee.
With six minutes left of normal time, the killer second goal arrived when Daniel Powell broke down the left channel, opened his body out and side footed clinically into the corner of the net. It was a little cruel on the Yeovil side that had battled well but failed to take their chances.
Six minutes of stoppage time could offer nothing more than a Hiwula effort that was saved by Martin and Yeovil’s brief improved home form had ended in abrupt fashion.