Two second-half goals were enough to give Port Talbot a pre-season friendly win over the Swans Under-21s.
After a slow first half in which neither side failed to create any clear-cut chances, the hosts took the lead on the hour mark through a superb strike from Sacha Walters.
James Loveridge and substitute Rory Donnelly hit the woodwork for the visitors, while Oli Bowen wrapped up the win for the Welsh Premier League side with a cool finish.
Recent recruit Jerneade Meade lined up in defence, while summer signing Alex Gogic started in midfield alongside Kurtis March and Henry Jones.
Rory Donnelly, who has been in good form for Michael Laudrup's first team in pre-season, started on the substitutes bench.
Both sides struggled to implement their passing game early on as the surface played havoc with the bouncing ball.
However, it was the Swans who created a good chance after just eight minutes as Cypriot midfielder Alex Gogic played a wonderful ball over the top of the defence, but Ryan Hedges saw his tame effort comfortably saved by Steven Hall.
With passes going astray and touches unpredictable, neither side could really create any clear-cut chances in the opening period.
The best that the home side had to offer was two opportunities from David Brooks. The winger's first chance flew a couple of yards wide of the right-hand post, before he was later through on goal but saw his curling shot drop over the crossbar.
Half time: Port Talbot 0 Swans Under-21s 0
The Swans came out of the blocks quickly in the second half as they looked to put their hosts on the back foot.
Despite suffering an early scare as Gregor Zabret tipped a shot over, O'Leary's men began to exert some control of proceedings.
Midfielder Alex Gogic was a prominent figure, and he saw a shot deflected just wide before the young Swans were denied what looked like a clear penalty when James Loveridge was tripped in the box.
However, just as the tide was turning, the home side broke the deadlock.
After Sacha Walters's corner was cleared back out to him, the defender took the ball down on the right corner of the penalty area before firing an unstoppable half volley past Zabret and into the top corner.
The Swans came close to a leveller just two minutes later, however, as Loveridge turned his man before racing clear and seeing his shot deflected back up and onto the crossbar.
Kristian O'Leary introduced Rory Donnelly and Spanish trialist Pau Moier from the substitutes bench, but it was the hosts who doubled their lead with just over ten minutes to play.
After breaking up a Swans attack in midfield, Walters fed substitute Oli Bowen inside the box and he made no mistake by tucking the ball past Zabret.
The Swans continued to press and they came close to pulling one back when substitute Rory Donnelly saw his chip come back off the woodwork, while the Northern Irishman also saw a late effort fly a fraction wide.
Swans Under-21s: Oliver Davies (Gregor Zabret, ht), Joseph Jones, Daniel Alfei (Liam Shephard, ht), Scott Tancock, Jernade Meade, Kurtis March (Steven Fallon, 77), Alex Gogic (Sam Evans, 72), Henry Jones (Rory Donnelly, 63), Kenji Gorre (Alex Bray, 72), James Loveridge (Pau Moier, 63), Ryan Hedges
Subs: Gregor Zabret (GK), Alex Bray, Sam Evans, Liam Shephard, Tom Atyeo, Pau Moier, Steven Fallon, Rory Donnelly