Two predatory finishes from Izale McLeod looked set to hand the Dons the points until James Hayter gave the Cherries hope and their new loan signing from Southampton lobbed home in the 90th minute.
Bournemouth started the game brightly with James O'Connor and Hayter both fizzing efforts wide from long range in the opening five minutes.
But the Dons began to find their feet and after Dean Lewington curled a left-footer just wide from the edge of the box, Bournemouth goalkeeper Neil Moss was quick off his line to block at McLeod's feet following Wade Small's incisive through ball.
The Cherries came close to breaking the deadlock on a swift counter-attack midway through the first half when towering striker Steve Fletcher's knock-down was smashed just wide by Surman with goalkeeper Matt Baker well beaten.
But the visitors were made to pay for that miss when McLeod calmly opened the scoring for Milton Keynes four minutes before half time following a superb passing move started by Small in his own half.
After a couple of neat one-twos instigated by Small, new signing from Hull Aaron Wilbraham held up the ball on the edge of the box before slipping in McLeod, who rounded Moss and slotted into the empty net.
Sean O'Driscoll's side almost hit back immediately when the impressive John Spicer's sweet 20-yard strike crashed against the post as the first half drew to an entertaining close.
But within 51 seconds of the re-start the Dons were 2-0 ahead thanks to another well-taken McLeod goal.
Small slotted the speedy 20-year-old hitman clean through and he again made no mistake, clipping the ball past the on-rushing Moss and into the corner of the net.
The visitors upped their game and it took a tremendous save from Baker to deny the livewire Hayter after he cut in from the left and unleashed a fierce drive.
But Hayter was not to be denied and he pulled a goal back for Bournemouth with a neat header in the 76th minute.
Neil Young's long throw was not cleared properly and after some scrappy head tennis the ball fell kindly for him to head home from just five yards.
And then in the last minute, Surman, who only signed on Wednesday, latched on to Brian Stock's through ball before lobbing Baker to break Dons' hearts.