With Corus losing 22-13 at Pontyberem, Dunvant took full advantage to record a 43-16 win over Quins, with left winger Mitchell Ford and flanker Rory Gallagher each scoring two tries.
Tonmawr recorded the biggest win of the day, belting Seven Sisters 57-5 on the back of a hat-trick of tries from winger Martin Morgan. Centre Ken Morris grabbed a couple and outside-half Austin Howells kicked seven conversions and a penalty goal for a personal haul of 17 points.
Loughor and Kidwelly fought out an entertaining 27-all draw, with Loughor winger Ian Wright snatching a share of the points with a late try. Mumbles are still looking for their first win after a frustrating 21-18 loss at home to Carmarthen Athletic, but Banwen are finally on the board with a 20-16 victory at Gorseinon, who slip a couple of places in the table.
In Division 3 West, Trimsaran and Penclawdd continue their battle at the top of the table after both sides recorded big wins on Saturday.
Trimsaran fullback Thomas Bollell (four) and right winger Mark Davis (three) helped themselves to tries in a 71-12 thumping of bottom-placed Hendy, while Penclawdd ran out 47-20 winners at Pembroke Dock Quins. Tumble's impressive 30-3 win over Lampeter was their first victory of the season.
Pontarddulais have stretched their lead to five points in Division 4 West after the match between nearest rivals Neyland and Llandeilo was postponed. Pontarddulais beat Milford 34-14, with braces of tries to outside-half Jonathan Lloyd and backrower Nic Walters.
In Division 5 West, Llanybydder winger Ken Payne helped himself to a hat-trick as the leaders trounced cellar dwellers St Davids 56-0, while second-placed Burry Port beat Aberaeron 22-9 thanks to three tries from scrum-half Rhodri Morris.
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.