Tredegar won the Division Two East title in spectacular fashion as they put 15 tries past Fleur De Lys.
The Gwent based club were presented with the championship trophy after their 95-14 demolition job, in which winger Damian Smith scored three tries to become the first player in the club's history to score hat-tricks in three consecutive games.
Smith was not the only hat-trick hero, as Daffyd James and Jamie Henthorne matched his feat, and Rob Smith came close after crossing twice.
Club captain Jack Dawson, playing his 100th game for the club, capped off a dream day by grabbing a try, along with Greg Jones, Darren Pearce and David Ford.
Garndiffaith also took a league title, winning both promotion and Division Three East on the same day after a 38-17 win over Gwernyfed.
Garndiffaith, who lifted the trophy at their Lasgarn View home afterwards, ran in six tries with scrum-half Rhodri Jones notching two. Andrew Gunter, Gareth Jones, Matthew Billings and Chris Baldwin picked up the rest.
Llandaff haven't quite guaranteed promotion from Division Four East, but they are now mighty close to doing so after their win at Crumlin. Ezra Huckle, Adrian Walsh and Barry Greenley all touched down for tries in a 24-21 victory.
With Nantyglo slipping up at Brynithel 26-21, Llandaff know a draw against Risca on Tuesday night would be enough to see them up. Abercarn aren't up yet in Division Five East, after they were beaten 20-3 by second-placed Talywain.
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