The hosts dominated possession early on, applying sustained attacking pressure. Yet they struggled to break down a well-drilled Palace backline, expertly led by captain Luke Browne.
Just before the break, however, Wimbledon found a breakthrough. A dangerous inswinging corner was met by Joe Lewis, who rose highest to head home. It was a harsh end to a first half defined by grit and discipline from the young Eagles.
Palace responded well after the break. On the hour mark, a moment of individual brilliance brought them level. Asher Agbinone drove into the box with purpose, skipped past his marker, and was clipped by a trailing leg. The referee pointed to the spot.
Agbinone stepped up, kept his composure with a stuttered run-up, and coolly slotted the ball home.
With momentum behind them, the young Eagles pushed for a second. But in committing bodies forward, they were caught out at the back. Antwoine Hackford broke free and finished past the advancing Lee to restore Wimbledon’s lead.
The hosts wrapped things up late on. Kai Jennings, making his debut, reacted quickest to a rebound after 'keeper Harrison Lee did well to parry the initial effort — sealing a 3-1 win for Wimbledon. Palace U21s are bottom of Group E in the EFL Trophy.
Take a look at the best of our photographers' images, captured throughout the night, in our gallery below.