Though victory was deserved with a 4-1 try-count, neither side played to expectations and it was not a good showpiece for the Division with both sides and the referee making far too many errors.
Fly half Chris Anderson, a former Neath player, opened the scoring with a penalty, but Neath hit back with a brace of tries by wing Richard Johnston, of which James Hook converted the second.
Two more Anderson penalties followed, but both he and Hook failed with attempts until Hook succeeded on the hour for a 15-9 lead. Neath skipper Gareth Morris then scored a try that Hook converted, but Cardiff replied with a dubious score from Chris Czekaj.
Another Hook penalty was followed by a corner try from Neath centre Andrew Bishop in the closing minutes.
WRU International Skills Coach Jason Strange is a busy man, combining the new role with that of Wales Under 20 attack coach, Ebbw Vale head coach and continuing to teach at Ebbw Fawr Learning Community.
Warren Gatland and Sam Warburton look ahead to this week's crunch RBS 6 Nations tie against France, where the Wales skipper in particular is keen to make his mark, as Paris has proved a bleak place for him in the past.
Following their historic win over England, Wales Under 20 suffered a narrow, 36-34 loss to their Scottish counterparts last weekend, despite outscoring them by five tries to three. Watch the match highlights and reaction.
WRU TV go behind the scenes with the Wales squad as they put the final touches in place ahead of the clash against Scotland at Murrayfield. Follow the squad on their captain's run, the kickers visit to Murrayfield and Neil Jenkins' press conference