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.
The last five years have been an emotional rollercoaster on and off the pitch for RGC1404. Promotion to the Principality Premiership was the culmination of five years of hard work and investment in North Wales. WRU TV caught up with prop Joe Simpson, who was one of the first intake of WRU North Wales Academy players in 2010.
Ebbw Vale captain Damien Hudd picked up the biggest accolade of the night at the 11th Principality Premiership Awards Evening held at Principality Stadium, after leading his side to the title for the first time.
Wales assistant coach Robin McBryde is predicting a tough battle against England on Sunday despite the fact they may not be considered to be at full strength. Players will be out to impress Eddie Jones which makes England a dangerous proposition, he says.
Wales U20 captain Tom Phillips and performance psychologist Dr Rich Neil explain why spending three days at Monmouth RFC has further strengthened the togetherness of the squad ahead of the #WorldRugbyU20s