Llandeilo began life in Division Three West with a spring in their step following a valuable 16-10 home win over Morriston.
The promoted outfit had fly-half Kelvin Davies, who also kicked two penalties and centre Glyn Jones to thank for tries in either half.
There was a clean sweep of home wins in the rest of the league with Crymych, Lampeter Town, Laugharne and Penclawdd all getting off to a flying start.
It was the same scenerio in Division Two West where the home side's ruled.
Waunarlwydd beat Mumbles 25-15 after tries from hooker Lee Brooks and full-back Johnny Lewis together with five penalties from fly-half Jonny Davies sealed the win.
Loughor started the season on a winning note by defeating Pencoed 19-14.
The hosts took control and a commanding 11-3 interval and edged home thanks to tries from wing Liam Hedges and scrum half Steven Wake.
Fly half Ben Davies scored nine points but Pencoed opposite number Mark Davies went two better by contributing 11 points with a try and two penalties. But his hopes were in vain along with and replacement fly-half Tom Cross' late drop goal.
Full back Dafydd Lewis grabbed a brace of tries for Kidwelly, who beat Aberavon Quins 21-6 at Park Stephens.
Promoted Pontyberem were also victors on the opening day but they had to come from behind to beat Ammanford 14-10 at home.
Mike Sauro kicked a trio of first-half penalties for the home side before centre Iwan Harris grabbed a late try to clinch victory.
In Division Four West, Chris Moore impressed with 15 points to seal a win for promoted outfit Cefneithin over Amman United.
Wings Luke Jenkins and Owain Lewis and hooker Will Holbrook also got in the act with tries in the 32-16 win.
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.