The U18's fell to their first defeat of the season on Saturday, to end their 3-match winning streak, at the University College London against Watford.
Danny Cadamarteri's side took the lead through Michael Fowler, the striker headed home a corner for his fifth goal in four games.
Watford then pulled one back shortly after, before Kian Yari poked home to give the Clarets the lead once again.
The home side then went on to equalise just before the break.
And Watford struck three more goals in the second half, before defender Bobby Thomas pulled back a late consolation goal, after heading in Matty Rain's cross.
Assistant manager John Townson said "Today we were punished for giving away the ball sloppily in the wrong areas. You cant score three away from home and lose the game, the players have to learn from this and move on and look to perform next Saturday against Ipswich and I'm sure they will"