Llantrisant stormed four points clear at the top of SWALEC League Division Two after capitalising on Gilfach Goch's slip at Bedlinog.
While the early leaders were being kicked out of first place by Bedlinog's Richard Heath, who kicked four penalties to edge out Gilfach Goch 12-6 in a tight encounter, Llantrisant were making far easier work of Treherbert.
Second-row Sam Williams scored twice as Llantrisant ran in seven tries to take an early grip on the division ahead of their rivals.
Tredegar slipped to third after losing 31-24 to local rivals Brynmawr for whom flanker Gavin Napp scored twice while at the other end of the table, Fleur de Lys claimed their first win when Richard Jones' late try beat Rhydyfelin locked at 25-18.
Llanishen enjoyed themselves in the sun with a 52-6 win over Cardiff rivals Old Illtydians in Division Three south-east
while Treorchy gained another bonus-point win at Aberdare, 35-20.
Gwernyfed and Garndiffaith lead the way in Division Three after their victories, 29-7 at New Tredegar and 29-15 at Cwmbran respectively.
Barry Greenley, Paul Rees, Chris Voyce, Stuart Ornick and Nathan Rhys all scored as Llandaff lowered the colours of Division Four leaders Nantyglo, 29-21 in Cardiff to take over top spot themselves.
In Division Four south-west, Dowlais had little trouble dispatching Porth 48-12 while Jack Davies and Gavin Stokes both scored twice as Abercarn produced the performance of the day in Division Five East, beating Llanhilleth 37-7.
Barry scrapped out a second tight victory in a row, getting the better of Cilfynydd 12-7 in Division Five south-east.
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
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.