That victory provided Dunvant with their first points of the season, although the highly competitive nature of the division they have dropped down into is emphasised by the fact there are five unbeaten teams ahead of them in the table.
BP Llandarcy moved to the top of the pile courtesy of their 14-10 victory at Mumbles, while Maesteg had a single try in their 13-9 victory at Pencoed to thank for holding onto their unbeaten status.
Newly promoted Pontyberem, who only lost once in 22 league outings last season, made it two out of two as they toppled their fellow promotion side, Aberystwyth, 17-16. But they had to do it the hard way away from home, hitting back from 16-0 down.
Loughor also had a narrow squeak as they kept their record intact, winning 25-22 at Ammanford despite being outscored 2-1 on tries.
Two dropped goals from skipper and outside half Iestyn Crompton ensured Cardigan completed an amazing second half revival to beat Llandeilo in Division 3 West. The visitors were 11-0 ahead at the break before Crompton struck, clinching victory in the fourth minute of injury time with his second goal.
Crompton converted tries from home back row men Dylan Davies and Gethin Davies to set up his late, late victory shot which left Llandeilo shattered as they went down 20-18.
There was a try hat-trick for centre Carl Gabrielson in Tumble's 42-7 win at Tenby United in Division 4 West, while Amman United also enjoyed a big win on the road, running in six tries in their 41-6 triumph at Pembroke Dock Quins.