This came after second-place Newbridge dropped two points in a 27-27 draw with Merthyr, despite scoring the four tries needed for a bonus point. Lenny Woodard, Gary Will and Ken Young were crossed for Newbridge, who also scored a penalty try, but Darren Davies hit a hat-trick to ensure Merthyr gained a draw.
Newport Saracens remain rooted to the bottom after being thrashed 57-14 by UWIC, with Alan Awcock, Ed Tellwright and Matthew John all scoring two each for the eight-try students.
Penalta picked up a losing bonus point as they fell 13-6 at Beddau, Caerphilly ran in five tries to beat Bargoed 43-21 and Ystrad Rhondda won 26-17 away at Rumney.
At the top of Division One West, Carmarthen Quins remain 23 points clear at the top after beating Maesteg 31-3 on the road. Winger Ryan Llewellyn scored in each half, with Andrew Thomas and Gareth Cull adding further tries to earn Quins their 11th bonus point of the season.
Second-place Tonmawr scored nine tries in a 62-3 victory over Felinfoel, Gareth John and Aca Ratuva grabbing two each.
James Pike and Mark Harvey scored two tries each for Corus, who won 31-3 against Dunvant.
Bonymaen won 14-10 at Llangennech, Cwmllynfell were 19-14 victors at Whitland and both sides scored four tries in Narberth's 30-27 win at Carmarthen Athletic.