Llanharan again kicked their heels as the other unbeaten club, Maesteg went to Beddau and won 29-6, while a late Whitland burst took them to a 50-10 win against Rumney on Cardiff University's ground and Narberth won well, by 35-14 at Blackwood.
Llangennech scored five unconverted tries in a 25-10 victory at Brynmawr, the students of UWIC beat Bonymaen 27-17 and Treorchy lock Jamie Summers
returned from a spell with Aberavon to score three tries in a 30-10 win over Tondu.
Tredegar moved to Abertillery Park, but two tries from skipper Stuart Jarman could not save them from a 39-18 beating from Carmarthen Athletic.
Fleur de Lys gained revenge for their Konica Minolta Cup defeat to Abercynon with a solid 26-13 victory in the East. And to make the win taste all the better, Fleur move above their opponents to third place in the table with Glen George, the player-coach and former Wales cap, scoring one of the three tries.
Builth Wells took full advantage of Merthyr's inactivity by winning 30-16 at Rhymney netting five tries; Llantrisant pulled away in the second half for a
resounding 48-17 success at Dinas Powys and Ystrad Rhondda beat Hirwaun 29-9 to move further away from the lower reaches.
In the West, bottom club Aberavon Quins again failed to appear and they have only completed 11 league games this season, at least five less than other clubs in this division.
Tonmawr held on to beat Newcastle Emlyn 19-18 to stay level second with Corus who won 22-8 at Cardigan. Vardre climbed some much-needed points with a 16-13 victory at Felinfoel but Birchgrove fell to their 14th defeat of the season after a home defeat by Cwmavon.
Cwmllynfell's promotion hopes took a knock after a 26-21 loss at Bridgend Athletic and Pencoed hung on to record a 17-14 win at Waunarlwydd.
Beating Merthyr has boosted Carmarthen Quins hopes of reaching a top eight spot in the Principality Premiership. Quins captain Haydn Pugh is delighted with his team's progress and is determined that everyone from the Under 6s through to the senior team, enjoys the ride.
When the Wales squad were asked to nominate individuals who played a big part in their early playing days, Wales and Dragons full back and wing Hallam Amos thought of his former Monmouth School rugby coach John Bevan.
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series