United drew 1-1 with Strikers FC in the Globe competition at the Milk Cup but were beaten 4-3 in a penalty shoot-out.
At least the result means there will be a chance to avenge the costly defeat to Co Tyrone in the Reds' final match of the tournament on Thursday. The game will kick off at 1.30pm at Castlerock.
After falling behind in the seventh minute, Irish striker Sam Byrne levelled just before the break with a header from a left-footed cross. There were no goals in the second half so a shoot-out was required to separate the two sides.
James Weir, Joe Rothwell and James Wilson all converted their spot-kicks but Andreas Pereira hit the bar. Josh Harrop needed to score to keep the Reds in the tie but he missed to cue celebrations from the Strikers.
United: Gollini; Weir, McConnell, McNair, Grimshaw (Rothwell); Redmond, Pereira, Goss, Harrop; Fletcher (Pearson), Byrne (Wilson).