Ystrad Rhondaa maintained a vice grip on first place dispatching Ynysybwl 42-19 in a six try romp. RGC 1404 kept up their pursuit of Ystrad by walloping Mountain Ash 54-12. Mountain Ash were outscored by six tries to three.
Treorchy turned over Rhydyfelin in a narrow 12-10 victory to cement their place in the top four. Merthyr's woes continued as they slumped to an 18-12 defeat at Penallta. Heol Y Cyw edged Gilfach Goch 15-7 to move away from the bottom-table battle.
In SWALEC Division 2 East, Nelson succumbed to a shock 34-28 defeat at home to Senghenydd and relinquished first position. Bedlinog surged to the top after battering Rhymney 43-3.
Llantrisant narrowly avoided suffering a stunning defeat at strugglers Tylorstown. Tylorstown won their first point of the season in the 21-19 loss.
Fleur De Lys outgunned Llanishen to triumph 16-10. Rhiwbina remain third after a functional 20-12 win at Pill Harriers. Abercynon's match with Llantwit Fardre was postponed due to a frozen pitch.