Newbridge were the cup kings after they produced the biggest upset of the fourth round in the SWALEC Cup.
Joe Calzaghe's hometown club gave Bedwas a knockout blow by dumping out the top flight outfit in a 18-15 triumph at Bridge Field.
The Division One East leaders trailed by just two points at half-time after a brace of tries from Lenny Woodard cancelled out scores from Jimmy Norris and Deri Mattravers.
But the match was decided by centre John Hawker's try on the 55th minute, which was the only score of the second half.
Bedwas failed to recover and became the first and only Premiership team to depart the competition at the first hurdle.
There were routine wins for most of their Premiership counterparts, with Swansea picking up the biggest win of the fourth round, hammering Bala 104-3. Ospreys squad member Leigh Bevan crossed four times against the Division One North visitors.
Bridgend saw off local rivals Pencoed 37-6 at Brewery Field by running in six tries while Llandovery went one better in the 45-0 win at Beddau.
Welsh Premiership rivals Aberavon, Newport and Pontypridd also recorded comprehensive victories to ease into the fifth round.
But Pontypool were given a scare at Bonymaen before pulling through 13-5. Pooler went behind on ten minutes through a try from winger Robert Jones before first-half replies from Will Kershaw-Naylor and Calwyn Morgan gave the visitors a narrow 13-5 victory.
There was a dramatic finish in Llanelli, as Felinfoel led Caerphilly deep into injury-time. With the score tied at 31-31, having scored five tries to Caerphilly's four, the Carmarthenshire club looked to be heading through on the try count rule.
But Felinfoel lost their lineout with seconds remaining and outside-half Danny Ellis touched down under the posts to clinch victory for the visitors.
There was just time left for Ellis, a second-half supersub, to kick the conversion before the referee blew up to allow Caerphilly to go through 38-31.
Wales and Ospreys back row James King, who came through the North Wales age grade system, nominated North Wales Regional Community Rugby Manager Marc Roberts, in the WRU's 'Diolch' initiative where squad players thanked those who played a part in their rise to the top.
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