A converted try by outside-half Paul Smithson, the only points scored in the second half, was enough to seal the victory against visitors Glynneath, who are in eighth position.
The bottom-of-the-table clash between Aberavon Quins and Skewen was postponed due to a waterlogged pitch, but there were victories for Loughor away to Ammanford and a narrow win for Kenfig Hill at home to strugglers Carmarthen Athletic.
Waunarlwydd’s comprehensive 42-17 at home to Llangennech ensured they remained hot on the heels of second-placed Cwmllynfell, whose match against Kidwelly fell foul to the weather.
In Division 2, Builth Wells extended their lead at the league’s summit to three points following a 15-3 win at home to Aberystwyth.
Seven Sisters remain in second place after a convincing 40-13 win against Penclawdd. Lowly Taibach shared the points and the tries at home to fourth-placed Felinfoel after the match finished 31-31.
Tenby United and Newcastle Emlyn both enjoyed victories leaving them first and second respectively in Division 3. Tenby’s 10-9 away victory at Cardigan was significantly less convincing than Newcastle Emlyn’s 48-0 thrashing at home to mid-table Tumble.
Tycroes beat Betws away 18-3 to continue their eight-match winning run at the top of Division 4. Swansea Uplands remain second in Division 5 after putting 100 points past St Davids, who remain in last place and yet to record a victory.
