Much like the first team this week, MK Dons academy were undone by a last-minute goal at rain-soaked Cardiff.
Mike Dove's men were left rueing their luck on the long journey home from South Wales after matching the Bluebirds until the dying moments of the game.
A scrappy opening 15 minutes saw both sides struggle to gain the upper hand, and the Dons brightest moment came on 17 minutes when a spell of pressure saw Dean Lovegrove's cross cleared into the past of Ross Morley who shot wide from the edge of the box.
Sam Baldock's speed got him past the defence on 28 minutes, but he was fouled on the edge of the area, the referee waving away the appeals from the visitors. There were also penalty shouts when Lovegrove felled in the box, but again the luck was not with the Dons.
Jamie England fired a free-kick across the face of goal on 35 minutes as the Dons continued to look brighter towards the end of the half, and at the other end Rob Webb, pictured right, made a brilliant reaction save to keep the scores level.
Webb was called upon again on 51 minutes with another smart stop to his left, before Sam Page headed wide at the other end after a good cross to the back post by Morley.
Sam Collins was next on the act, a cross-shot screaming across the face of goal with no Dons attacker able to get the vital touch on 65 minutes.
Webb was continuing to play extremely well in goal, and he somehow got a fingertip to a well struck shot on 75 minutes, tipping the ball onto the crossbar and away.
And with the referee looking at his watch and about to blow for full-time, a speculative lob into the danger area saw substitute Adam Kent wrongfoot Webb with a wayward back-header which beat the keeper into the net.
Team: Webb, Howe, Murphy, Page (Nash), Collins (Kent), Battams, Day, Morley, England, Lovegrove, Baldock. Not used: Flood.