Jamie Ward's clinical brace had put the Gulls 2-0 up at half-time, but Izale McLeod's double and Wilbraham's 84th minute strike won it for the Dons before Lee Thorpe saw red at the death.
The Dons started brightly and Wilbraham should have done better when he scuffed straight at Torquay goalkeeper Nathan Abbey from seven yards in the fourth minute after the pacey Lloyd Dyer had skinned Lee Andrews down the left.
And Ward made him pay for that miss by putting the Gulls ahead following a swift counter-attack in the eighth minute.
Ward broke the offside trap to latch on to Matt Hockley's defence-splitting pass and coolly fired past keeper Adolfo Baines into the corner of the net from 15 yards.
Milton Keynes piled forward in search of an equaliser but Clive Platt headed Dean Lewington's superb cross straight at Abbey from 12 yards, Dyer's angled drive was deflected wide and Sean O'Hanlon headed Paul Mitchell's cross wide when well placed in the 37th minute.
Chorley was unlucky not to equalise for the Dons in the 40th minute when his header from Lewington's cross was cleared off the line by Hockley, before O'Hanlon scuffed Wilbraham's low cross badly wide from five yards.
And after Wilbraham had blazed another good chance over the bar three minutes before the break, Ward showed them how it should be done with another clinical finish at the other end to put Torquay 2-0 up in first-half stoppage time.
Ward raced clear on to Thorpe's long ball and composed himself before lobbing the on-rushing Baines to complete his brace.
The Dons burst out of the blocks after the break and McLeod pulled a goal back in the 50th minute from a twice-taken penalty after Andrews was adjudged to have handled a long ball in the box.
McLeod's weak first spot-kick was saved at full stretch by Abbey, but after the keeper was adjudged to have moved off his line, McLeod made no mistake from the re-take as he tucked the ball into the same corner.
Jon-Paul McGovern curled a 30-yard free-kick inches wide of Abbey's top corner before McLeod made it 2-2 with a superb individual goal to complete his brace in the 59th minute.
McLeod wriggled free on the edge of a crowded box before clipping a neat finish past Abbey and into the corner of the net from 16 yards.
Mitchell fired Lewington's quick free-kick across the face of goal in the 74th minute as the fired-up Dons pressed for a winner.
But Kevin Hill blazed wide of an open goal from 40 yards for the visitors three minutes later after Baines had raced from his line to tackle Thorpe.
And Wilbraham completed the Dons' comeback when he headed home McGovern's 84th minute corner from close range to snatch the win, before Thorpe picked up his second yellow card in injury time for a rash tackle on Lewington.