Referee Michael Oliver showed red cards to Mathias Doumbe, David McCracken and Peter Leven while Leeds substitute Jermaine Beckford scored twice to take his goal tally for the season to 30.
Doumbe was dismissed for a 43rd-minute tackle on Sanchez Watt, McCracken followed him after 85 minutes for bringing down Beckford inside the penalty box and Leven saw red in injury time for a dangerous tackle.
Luciano Becchio sprinted into the penalty box before tucking the ball inside the near post to score for the fourth successive game on 13 minutes, while the Dons equalised six minutes later, skipper Dean Lewington volleying past Shane Higgs from 10 yards after Leven launched a high free-kick.
Leeds regained the advantage after 33 minutes when Neil Kilkenny intercepted a pass and was challenged by Lewington just inside the box, with the ball bouncing kindly for Watt to find Max Gradel who calmly applied the finish from 12 yards.
Beckford volleyed Leeds' third from six yards with nine minutes left and then made no mistake from the spot on 86 minutes.