Llandovery stormed over for four second half tries to record a comfortable 48-14 victory over Newport at Church Bank.
The triumph puts the Drovers into a top three position with just Cardiff and Carmarthen Quins now above them.
The Drovers scored six tries - four in the second half - and all were converted by fly half Ian Brooks who ended with a personal haul of 23 points.
The Black and Ambers had the best possible start when hooker Dale Rogers plunged over wide out after just two minutes.
Drovers scrum half Rhodri Davies then took a quick tap penalty to set up a strong attacking position which eventually brought a close-range penalty for fly half Brooks but this was soon cancelled out by a good effort from centre Geraint O'Driscoll.
Wing Sam Soul and Brooks both threatened the Newport line but it was centre Matthew Jacobs that made the clean break that saw prop Wyn Jones send in Brooks at the posts for a converted try.
O'Driscoll and Brooks exchanged penalties but a yellow card for home lock Bryn Griffiths gave O'Driscoll the chance to make it 14-13 to the visitors. But an exquisite cut out pass from scrum half Davies sent centre Craig Woodall accelerating through for a try under the posts without a hand laid on him.
After playing into the wind and down to 14 men, it was a bonus for the Drovers to hold a 20 - 14 lead but another yellow card for Jacobs checked their momentum. Newport then lost both prop Dai Pattison and Gethin Robinson for 10 minutes and a surging scrum gave home No 8 Richard Bloomfield the opportunity to pick up and crash through.
Newport looked demoralised and a great run from young Wyn Jones ended with skipper and flanker Phil Day crossing. The Drovers were rampant and a Brooks run fashioned a try for replacement hooker Luke Lewis, soon followed by one from veteran prop Andrew Jones.
Wales reached their first semi-final since 2013 in the opening round of this season's HSBC World Rugby Sevens Series in Dubai. WRU TV's Graeme Gillespie recaps on what proved to be an eventful tournament
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