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.
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.