Three goals in the first 29 minutes put Grimsby in total control before Jon Mellish’s red card nine minutes from the break put the game almost out of reach.
A George McEachran own goal early in the second-half gave Dons a glimmer of hope before Connor Lemonheigh-Evans’ strike in the 90th minute set up a thrilling finale but it was too little too late.
Here’s how we rated the players at Stadium MK.
1. How we rated the MK Dons players in the defeat to Grimsby Town
The brunt of the damage was done in the first-half at Stadium MK | Jane Russell
2. Craig MacGillivray - 5
Twice beaten from close range and then a screamer in the opening 29 minutes. The second goal he should have dealt with better | Jane Russell
3. Jack Sanders - 5
Started on shaky grounds, and was beaten to the opener by Kieran Green. Recovered in the second-half and almost claimed a point with an overhead kick at the death | Jane Russell
4. Marvin Ekpiteta - 5
Like Sanders, looked shaky early on. Provided the assist for the own goal early in the second-half - a much better 45 minutes. | Jane Russell