Gorseinon are one victory away from the title – but Cowbridge are waiting right behind them in case they slip up.
Leaders Gorseinon extended their lead at the top to six points after beating basement boys Swansea Civil Service by seven wickets.
Relegated Civil Service were put in to bat and were all out for 81 as Jack Donovan took six wickets. Andrew Dyer and Kieran Howells took the remaining wickets with two apiece.
Ashley Pass struck 41 in the chase as Gorseinon knocked off the runs to keep their title hopes alive.
But Cowbridge are waiting in the wings after easing to a nine-wicket victory over Merthyr Tydfil. Cowbridge put Merthyr in to bat and it proved a wise decision as bowler Brad Evans was in inspired the form.
Evans claimed a stunning eightwicket haul, which included the dismissal of top scorer Rhys Boswell (10), to bowl Merthyr out for 40, and