Josh Morris inspired Treherbert to their first victory in over a year in Division Three South East following their 18-13 success against Penarth.
Treherbert went through the whole of last season without a single victory to their name but Morris made sure this is a fresh start after his sprint for the try-line from his own 22.
Scott Barclay also crossed on a famous day for the Rhondda valley club who had to face a late onslaught from the Seasiders who scored two tries of their own.
And it was a day of drama in the division as Tylorstown edged a thrilling 26-23 win over Heol y Cyw.
The home side scored through John Thomas and a penalty try while 16 points from Julian Pike sealed the victory.
Tries from Richard Howells and Kevin Worgan for the visitors ensured the opening clash went down to a thrilling finale but the hosts came out on top.
Division Three East saw Pontypool United and Abergavenny produced the biggest wins of the day while Pill Harriers and Nelson nicked victories over Tredegar Ironsides and Blaina.
Pontypool United beat Newport HSOB 49-7, crossing the visitors line for seven touchdowns while Abergavenny went one better by running in eight tries against Rhymney to win 47-20.
But the Brewers were hampered when their scrum half was carried off midway through the match with a suspected broken ankle. Jonathan White went over for a brace of tries for the losers.
Ynysybwl hit maximum points on the opening day to top Division Two East following a comprehensive 34-3 victory, 6-0 on try count, over visitors Llantrisant.
Gilfach Goch, Penallta, Treorchy and Llantwit Fardre all also recorded home wins with Rhydyfelin emerging as the sole away victors 24-15 at Abercynon.
Relegated clubs Penallta and Newport HSOB met in Two East and it was Penallta who ran out winners 13-5. In the same division, Mountain Ash earned a losing bonus after running Llantwit Fardre close with a 19-15 scoreline.
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.