MK Dons were beaten 2-1 by Southampton B in their final group match of this season's Papa John's Trophy.
Russell Martin's men, already secured of a place in the knockout stages of the competition, needed a point to make sure of top spot but fell behind to a Sam Bellis goal after 22 minutes.
Matthew Sorinola equalised within a minute of the re-start to momentarily give his side the point they needed.
However, Southampton would strike late to seal an away victory and force the Dons to wait until the result of the Northampton Town and Stevenage match, to see whether or not they would progress through as group winners.
Boss Martin named nine Academy products for the Papa John’s Trophy tie with Southampton B – with David Kasumu donning the captain armband for the first time in his career.
Charlie Smith and Lewis Johnson – who are both 16-years-old were handed their professional debuts by Russell Martin. Having been handed his first professional contract at Stadium MK this Summer, Jack Davies was also handed his first start in an MK Dons shirt.
Laurie Walker was once again back in goal for the Papa John’s Trophy with Baily Cargill, Carlton Morris, Scott Fraser, Lasse Sorensen, Matty Sorinola and John Freeman making up the rest of the starting XI.
Martin also used the competition as a chance to hand professional debuts to Malaki Black and Josh Bailey who were both second-half substitutes.
Dons had the first chance of the game and momentarily thought they had taken an early lead. Carlton Morris was played in on goal by Scott Fraser, a late flag denied the striker after he had slotted past Harry Lewis.
It was Southampton, however, who took the lead. Sam Bellis put pressure on Laurie Walker and managed to get a boot to his clearance. Unfortunately for the Dons keeper, it ended in the back of his net. 0-1.
Martin’s side looked to draw back level immediately and would’ve netted the equaliser if it wasn’t for some brave Southampton defending. Kasumu played a wonderful half-volley out to Sorensen, who took a touch to set himself before crossing. Just as it looked like Morris would head home, Tchaptchet headed clear.
From the resulting corner, the Dons went short before finding Fraser on the edge of the box. His shot was deflected narrowly over the bar.
With 43-minutes on the clock, Fraser was again involved, this time looking to turn creator. He made his way into the area before pulling back the cross to find Johnson on the six-yard box, his first-time strike rolled narrowly wide of the post.
Johnson once again came close this time from a Sorensen cross. The young forward done well to lose his man inside the area, however, was unable to divert the Dane’s cross towards goal.
With Louis Thompson replacing Scott Fraser at the break, the Dons needed just under a minute to level the scoring. Baily Cargill played a ball over the back of the Southampton defence that caught Lewis off guard. The Southampton keeper misjudged the flight of the ball leaving Sorinola with an empty net. 1-1.
Just 10-minutes later, Sorinola could've had his second of the evening, he was found by Freeman but was denied by the onrushing Lewis.
Louis Thompson was the next to go close, he was unable to keep his volley down as his shot ended over the bar.
The Dons then put together a free-flowing passing move down the right as Bailey played a one-two with striker Carlton Morris. Bailey then threaded into the path of Johnson, who saw his cutback for Bailey intercepted.
Southampton, however, won the game with minutes remaining, Kazeem Olaigabe intercepting Walker's pass to convert from close range. 1-2.
MK Dons XI: L. Walker, Cargill, Kasumu (C) (Bailey 61), Morris, Fraser (Thompson 46), Sorensen, Davies, Sorinola (Black 61), Freeman, Johnson, Smith.
Subs: Fisher, Lewington, S. Walker, Jerome.
Goal: Sorinola (46)