The Ironmen scored three tries, with Alex Howman, Dean Gunter and Gareth Way all touching down and full-back Matthew Jarvis kicking 18 of the visitors’ points. Jac Wilson and Keelan Giles stood out for Swansea, with a try apiece.
In a remarkable end-to-end struggle, the All Whites led 20-19 with 15 minutes to go, before Merthyr notched two late tries to claim victory.
RGC 1404 comprehensively beat Glynneath 64-15 in a bad-tempered match which saw three yellow cards and a sending off. The North Walians scored 10 tries – including two each from Tom Hughes and Danny Cross – despite being down to 13 men in the final quarter.
A tight match between Newcastle Emlyn and Tata Steel ended 34-33, with each team scoring four tries. The Saints fought back strongly, having gone 16-24 down in the first half, but their second-half heroics were to no avail.
Third-placed Pontypool picked up a bonus point against Bridgend Athletic, winning 31-7. A competitive first half gave way to a rout by Pooler, as the visitors failed to score a single point after the break.
Pontypool benefitted from two penalty tries and Clayton Gullis scored 11 points with the boot.
Cardiff Met came out on top in a closely fought tussle with Beddau, walking away 35-24 winners after a tight struggle.
Inside-centre Miles Moorehouse scored 12 points, and prop Alex Dombrandt bagged a brace for the Students. The match remained tight throughout, but Beddau fell behind in the last ten minutes.
Full-back Jonathan Morgan led Narberth to a 40-15 victory over Llanharan.
Narberth ran in five tries. including two penalty tries, while outside-half Ianto Griffiths kicked 15 points. The result means Llanharan are still searching for their first win of the campaign.
