Despite leading through Louie Barry’s brilliant solo goal, his first for the club, just before half-time, Hayden Roberts equalised two minutes later from a corner, with James Collins doing the same six minutes into the second half.
While Dons looked the more threatening, Nathaniel Mendez-Laing wrapped things up for the visitors with 11 minutes to go.
Here’s how we rated the players at Stadium MK.
1. Jamie Cumming - 5.5
Beaten at three set-pieces, although one was ruled out for offside, which will be of huge frustration for him. Otherwise, untested from a shot from a Derby player. Photo: Jane Russell
2. Dean Lewington - 5.5
A tricky start and too many set-piece goals marred the skipper's appearance Photo: Jane Russell
3. Zak Jules - 6
A couple of driving runs forward give him extra marks over his centre-back counterparts, but the set-piece goals were a huge issue Photo: Jane Russell
4. Warren O'Hora - 5.5
Part of that back line which never dealt with Derby's aerial threat. Photo: Jane Russell