In the other game played, Pencoed Phoenix secured their first scalp of the season with a 17-7 win against Bonymaen.
Bonymaen scored a converted try through Sophie Moore, but their hosts proved too strong and ran away with tries from Leanne Burnell, Linzi Morgan and Katie Murphy.
Llandaff got off to a flier in their first game of the season, scoring an early converted try but Pontyclun were quick to reply with a try from Zoe Lewis. Brogan Jones’ conversion took the visitors ahead 7-5 with just 10 minutes on the clock.
Wales international Robyn Wilkins edged Llandaff North back in front with a try in the corner before the lead was extended by Elin Huxtable for the third try of the game. Claudia Meyrick’s conversion took the lead to 17-7.
Wing Catherine Richards cantered over to score the bonus point try with Meyrick’s conversion taking the lead to 24-7.
Pontyclun reduced the arrears just before halftime with a converted try through Jordan Hopkins but they suffered an early setback in the second spell when Wilkins dotted down for her second try of the match, converted by Meyrick.
A try from speedster Rafiuke Taylor and a penalty try saw Pontyclun reduce the arrears but they ran out of time as Llandaff North held on for the victory.
Three tries inside the first quarter through Lowri Norkett, Amy Morgan and Jodie Evans put Swansea firmly in control against Burry Port at Memorial Park before the match was abandoned because of a serious injury.
