Corus recorded their fifth straight win with a 29-22 result in an entertaining, seven-try match against Kidwelly. Lewis scored two tries and kicked nine points as the league leaders kept their noses ahead of Dunvant, who made it four out of four with an impressive 30-3 win at Carmarthen Athletic.
Gorseinon were the only other team who went into Saturday's games with an unbeaten record, but Bridgend Athletic took care of that with a well-deserved 20-13 win at home.
Seven Sisters fullback Kevin Lewis kicked four penalty goals as his side edged past Felinfoel 22-14 to record their second victory of the season. Loughor fullback Lee Davis matched Lewis' feat, his four goals providing all of his side's points in their 12-10 win at winless Banwen, while Maesteg Quins beat Tonmawr 17-3 and Pontyberem accounted for Mumbles 20-12.
Trimsaran and Haverfordwest are locked together at the top of Division 3 West, although Haverfordwest did it the hard way with an 18-16 win at winless Lampeter. Trimsaran cruised to a comfortable 27-3 victory over Newcastle Emlyn.
At the wrong end of the table, Tumble (35-19 losers to Aberystwyth), Lampeter and Hendy (18-5 losers to Tenby) are still looking to lose the duck's egg beside their names.
In Division 4 West, Pontarddulais continue on their merry way at the top after a 37-6 win at Cardigan, while second-placed Neyland were held to a 13-all draw at Milford. There was another draw in the division, with bottom-placed Llandybie earning their first point of the season courtesy of a 6-all deadlock at home to mid-table Ammanford.
Llanybydder are alone at the top of Division 5 West after their fifth straight victory - a 49-0 mauling of Pontyates - although Burry Port also retained unbeaten with a gritty 22-18 victory at Tycroes.
Pontyates are one of three sides still looking for their first win. The two Saints - David and Clears - are holding up the table after St Davids fans had to sit through a 57-6 hammering at the hands of Gowerton and St Clears fell 16-36 at home to a Llangwm side celebrating their first win of the season.
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.