Somewhat against the run of play, MK Dons opened the scoring when Tennai Watson was played in and he beat Mike Cooper.
With a little over 20 minutes to play, Conor Grant equalised after he started the move with some neat build-up play.
Story of the match
The Pilgrims had the first chance of the match 12 minutes in as Camara let fly from 25 yards out, but his effort was well over the bar.
Moments later, MK Dons were in front as Scott Twine played the ball in behind Macaulay Gillesphey for Watson to run on as he beat an on-rushing Cooper.
Plymouth nearly equalised immediately when Andrew Fisher made a fine diving save from Grant's 20-yard shot.
A number of fouls were committed in a first half bereft of much fluidity or excitement.
The Pilgrims had much of the possession to start the second half, but failed to create any noteworthy chances against the Dons' defense.
Mayor was introduced as a substitute in the 62nd minute and he would soon play a role in Plymouth's leveler four minutes later.
Grant and Gillesphey combined to release Mayor, who crossed to Camara. The Guinean played it back to Grant, who beat Fisher with a right-footed effort.
MK Dons had a sub of their own that nearly made a decisive impact as Troy Parrott clattered a shot against the bar in the 70th minute.
Garrick nearly grabbed a winner late on as he cut inside onto his left foot and his shot smashed off of the left post.
Man of the match: Conor Grant
He had the goal that earned Plymouth a point and was also involved in some of the more positive passages of play in a game that lacked much quality.