Swans U21s went down to a 3-2 Friendly defeat to Exeter in Llanelli on Tuesday night.
After falling behind in the 12th minute, Kristian O'Leary's side drew level two minutes later at Stebonheath Park after James Loveridge struck.
Exeter regained their lead just before the break, but a Rory Donnelly effort five minutes after half-time levelled the scores.
The visitors, though, weren't to be denied victory as they struck just past the hour to take the lead which they held on to.
For the Swans, Mark Gower featured for 69 minutes while Alan Tate
played for the whole game.
O'Leary also gave run-outs to two Under-16 squad members in Owain Jones and Cai Owen, both coming off the bench, as they gained further experience.
David Cornell, Nathan Waters (Liam Shephard, 60), Luke Llewellyn (Cai Owen, 77), Mark Gower (Josh Sheehan, 69), Alan Tate
, Scott Tancock, Luke Williams (Alex Samuel, 77), Lee Lucas, Henry Jones (Owain Jones, 77), Rory Donnelly, James Loveridge.