Argyle ace Simon Walton fired the home side ahead from a 21st-minute free-kick from the left following a foul by Dons central defender Sean O'Hanlon on lively winger Yannick Bolasie.
Walton - a revelation since returning from injury - swung in his free-kick from 25 yards and the flight deceived Dons goalkeeper David Martin, as well as eluding recalled Plymouth striker Rory Fallon. Argyle will now climb out of the bottom four if they win their game in hand.
After seeing his side record successive 1-0 wins over Easter, Reid said: "The lads have given themselves a great shout, a fighting chance, and that`s all you can ask. It's going to be difficult because the game in hand is a very difficult one (against Southampton) and we now have to concentrate on our next game, which is a local derby against Exeter, and everyone knows about local derbies.
"It's another win, it's another clean sheet; that's two 1-0 wins and two clean sheets. Fantastic, I couldn`t have asked for more. The players have been magnificent and I`ve said it before but now I am running out of things to say about them.
"They defended superbly, showed their determination, their character. I thought MK Dons were the better side, I thought they passed it better, worked us all over the place, but for sheer endeavour, character and grit, you know, tremendous from my players."
Source: PA
Source: PA