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.
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
Alongside Scarlets flanker James Davies and Cardiff Blues centre Cory Allen, three Wales Sevens core players have made the extended training squad for GB Sevens. Wales Head coach Gareth Williams tells WRU TV's Graeme Gillespie why Luke Treharne, Sam Cross and Luke Morgan earned selection in the initial training squad for Rio.