A stoppage time penalty from Lee Gregory saw Millwall secure all three points as MK Dons went down 2-1 at The Den on Saturday.
Paul Downing was adjudged to have pulled back the Millwall striker in the second minute of stoppage time to give away the spot kick, which Gregory duly rattled home with aplomb.
With long balls the order of the day, Gregory's 25th minute header opened the scoring for the home side. But having kept nine consecutive clean sheets prior to kick off, Ben Reeves drew Dons level barely five minutes
Robbie Neilson made three changes to the side which started the 2-2 draw with Bradford City in the week, with top scorer Kieran Agard returning, along with Darren Potter and Ben Reeves.
It wasn't an attractive opening 25 minutes to the game. Both sides lumped long balls at each other, with the balding playing surface bobbling badly. Passes amongst themselves were proving troublesome for both sides as possession changed hands readily.
Dons' lack of phyiscal presence has been known problem to Robbie Neilson since his arrival at Stadium MK, so it came as little surprise when 6ft2in striker Lee Gregory towered over the Dons defence to powerfully head home Shane Ferguson's cross after 26 minutes.
Neil Harris' side had nine consecutive clean sheets heading into the game, but Ben Reeves put a blot on the copybook when, just four minutes after the opener, he broke the run with an excellently taken left-footed strike from the edge of the box to equalise.
The stale affair continued into the second half with neither able to get their game going along the ground. Veteran striker Steve Morison though had to do better within seconds of coming on, finding space after three Dons defenders went for the same ball, but he dragged his shot well wide of the mark.
Certainly not a game for the purists, Dons struggled to keep hold of the ball for more than two or three passes at a time as the physical Millwall side dominated territory, but struggled really to create anything. The closest they came was a Ben Thompson strike from the edge of the box with 11 minutes to go, forcing David Martin low to his right to keep out the effort.
Dons missed the best chance of the game though with four minutes to go as two substitutes combined. Nicky Maynard pulled away on the right flank to whip the ball across, but it looked like it caught Dean Bowditch by surprise as he was left unmarked at the far post, heading over with the goal gaping.
But Gregory would have the last laugh, rattling home the stoppage time penalty after Paul Downing pulled down the striker.
To rub salt into the wounds for Dons, bookings for both Dean Lewington and George Baldock mean they will both be banned for the next two games.
Referee: Ross Joyce
Millwall: King, Cummings, Craig, Williams, Thompson (Butcher 88), Gregory, Onyedinma (Morison 55), Webster, Ferguson (Wallace 72), O'Brien, Cooper
Subs not used: Girling, Hutchinson, Worrall, Romeo
MK Dons: Martin, Baldock, Downing, Walsh, Lewington, Williams, Upson, Potter, Reeves (Maynard 74), Muirhead (Bowditch 84), Agard (Barnes 58)
Subs not used: Nicholls, Ngombo, O'Keefe, Tilney
Booked: Ferguson, Thompson, Walsh, Martin, Lewington, Gregory, Baldock, Morison