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.
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.