Feruz and a deflected Isak Ssweankambo shot threatened for the Londoners before the game turned on a critical minute. Ben Pearson won the ball expertly to advance through and shot too close to Blackman and, seconds later, Charni Ekangamene's touch fell into the path of Baker, who guided a clinical finish into the corner of the net.
Michael Keane headed over the bar as Warren Joyce's youngsters tried to rally with Amos going up for a corner that ended in Weir having a snap-shot saved by Blackman. Substitute Tyler Blackett had one final attempt that forced a great save out of Blackman deep into stoppage time. However, there was no way past a well-organised defence as United relinquished the trophy, but not without a splendid effort all season.
United: Amos; Varela, McNair, M.Keane, James (Blackett 82); Janko, Ekangamene, Pearson, Lawrence (Harrop 86), A.Pereira; Wilson (Weir 68). Subs not used: J.Pereira, Willock.