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.
GB7s women left their England base to train in Wales this week. Olympic Games hopeful Rachael Burford gives WRU TV's Graeme Gillespie her thoughts on Welsh teammate Jasmine Joyce - a 'one touch wonder'
The GB7s women's squad is currently training at Wales' Centre of Excellence where assistant coach Richie Pugh tells WRU TV's Graeme Gillespie some 'tough calls' will have to be made when it comes to finalising the 12 spots for Rio's Olympic Games.
Wales U20's Billy McBryde is looking forward to starting his first game against New Zealand this afternoon in the World Rugby U20 Championship where his side are looking to gain revenge from last week's pool defeat to the Kiwis.