Dunvant were denied their first win of the season by a controversial injury-time try for Felinfoel.
The basement Division One West side had lost their previous 21 league matches this season. But they looked certain to break their duck before Luke Marsh touched down to secure a narrow 31-27 victory.
It was scrum-half Marsh's second score of the afternoon but the hosts claimed the ball had not reached the try-line.
Sam Crowley, Mike Arnold and Lee Tucker crossed for Dunvant but Felinfoel had already scored tries through centre Ryan Nicholls, fly-half Stuart Wall and former Dunvant player Simon Delaney.
Second-placed Tonmawr gained a bonus-point 33-10 away win at third-placed Narberth with wing Ryan Davies grabbing a double to assist Hywel Davies, Steve Lewis and Mickey Evans.
Cwmllynfell beat Carmarthen Athletic 34-22 and Whitland and Bonymaen shared the spoils in a 15-15 draw. Carwyn Jones scored all the points for the hosts with tries from Robbie Ford and Duane Eager.
Division One East Champions Blackwood hammered Caerphilly 86-24 thanks to hat-tricks from the James brothers. Both Trevor and David James crossed three times each in an 11-try blitz against the fifth-placed outfit.
Luke Knight added two tries while Mark Birkley and Adam Coupe completing the scoring while the home side scored consolation touch downs through James Walby, Keiran Phillips and fly-half Dan Ellis who claimed 14 points.
It was a try-scoring feast across the three games played in the division with UWIC running in eight tries in their 49-15 romp over Merthyr.
Bargoed moved into fourth place in the table with a convincing 29-15 victory over Rumney. The hosts raced into a 24-5 interval lead with wing Gary Jones grabbing a double along with Rhys Humphreys, Lewis Wayman and Danny Jones.
Despite drawing with Ireland in the opening round of the RBS 6 Nations, Wales defence coach Shaun Edwards believes the championship 'is still in our hands' as he prepares his side to face Scotland at Principality Stadium tomorrow.
Meet the members of the WRU's inaugural Youth Board - after an online selection process which saw a host of high calibre candidates submit video applications the WRU has made its first 15 appointments.The board is made up of individuals aged between 16 and 21, and will meet for the first time at Principality Stadium on Monday 15th February.
The Wales Women's team headed to Dare Valley Country Park on a team bonding exercise as the entire squad got together for the very first time in preparation for this season's Six Nations championship which kicks off on Saturday with a clash against defending champions Ireland, in Donnybrook.
Wales Head Coach Warren Gatland discusses his team selection for the opening round of the RBS 6 Nations where he leads his side against Ireland, on Sunday. As WRU TV's Luke Brodley discovers, Gatland is fully aware of the challenges the defending champions pose