Elsewhere Pill Harriers picked up a 25-6 win over bottom club New Tredegar, with Pill pair Craig Lloyd and Ross Palmer both crossing once in either half, scoring four tries for a bonus point between them.
Aberdare lost a fifth straight game in Division Three South East, falling 23-18 at St Peters, who scored three tries through Paul Davis and two from Sean O'Brien. Also in that division Llandaff North beat Penarth 33-24.
St Josephs beat Monmouth 14-10 in Division Four East's only surviving game. Pentyrch hit six tries as they smashed Senghenydd 40-3, with Gareth Ayres crossing twice as his team went top of Division Four South East thanks to their seven league victories