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.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.
Blues strike first in JD III battle - Newport Gwent Dragons lock Andrew Coombs, WRU referee Dylan Llyr Jones and Cardiff Blues hooker Matthew Rees decide dressing room allocations for Judgement Day III
Wales Under 18 captain Calum Haggett has received a conditional offer to read Biomedical Science at St Anne's College, Oxford. WRU chairman Gareth Davies went to meet Calum and Coleg y Cymoedd Principal Judith Evans to wish him luck in his exams and pass on some of his personal experience.
Dodgy tattoos, carthorses, Avatar and soft chins are revealed by Wales Sevens players Tom Williams and Sam Cross as they profile the Wales Sevens squad taking part in Hong Kong this weekend in the latest round of the HSBC Sevens World Series.