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.
Wales Head Coach Rob Howley talks to WRU TV's Sebastian Barrett about the 36-man squad he has just named for the forthcoming Under Armour series, which includes two uncapped players, Ospreys duo Sam Davies and Rory Thornton.
Head coach Rowland Phillips is deligthed he can now call BT Sport Cardiff Arms Park home for his Wales Women's side, who launch their international season next month with games against Scotland and UK Armed Forces in the heart of the capital city.
Wales Sevens star Sam Cross has put his home town club of Brynmawr on the map after winning a silver medal at the Rio Olympics with Team GB. His club have now honoured him by naming their players bar after him, as WRU TV discovered at the official launch, recently.
One of the newest members of the Principality Premiership, Bargoed admit it's proving to be a steep learning curve at the highest level, but are determined to become a force to be reckoned with. WRU TV visited the club last weekend when they took on Llanelli.
Table-topping Aberavon travel to north Wales to tackle RGC 1404 as both teams defend unbeaten starts to the season in the Principality Premiership. WRU TV's Graeme Gillespie visited the Wizards to see how their preparations were going for the game of the weekend.
The Half a Game initiative is currently sweeping across Wales and proving a major success. The scheme aims to give every young player at least half a game every weekend. WRU TV recently visited a festival in Narberth where clubs have fully embraced the initiative.
Both Bargoed and Swansea were seeking their first win of the Principality Premiership season this afternoon. It proved a fruitful day for the hosts - not only did they win, but Bargoed claimed a try bonus point.
Cardiff managed to keep their unbeaten record at home intact, but only just as Bridgend made them work extremely hard before the Blue and Blacks secured a hard fought Principality Premiership win at the BT Sport Arms Park last night.
Former Wales back row Andy Powell gives a guided tour of The Wern, home of Merthyr RFC, who are determined to prove a lot of people wrong and make their mark in their first season in the Principality Premiership.