Glyncoch of Division Six Central have been the surprise package in this season's cup tournaments and they will be the underdogs when they come up against New Tredegar of Four East.
But they will be keen to make it a cup and league double after securing the Six Central league title.
They have punched above their weight in every round, reaching the quarter-final with a thrilling 13-9 victory at Four South West outfit, Glyncorrwg.
Amman United of Four West were the next visitors and this tie was even more tense with Glyncoch edging through 18-16 to set up a semi-final against another Four East side in Talywain.
The Six Central side won through to the Millennium Stadium after a 24-21 victory with three penalties and a conversion from outside half Lee Goddard proving decisive.
"We've been building for the last few seasons and were unbeaten two years ago," said Glyncoch coach David Allen.
"We're unbeaten again this season and hope we can go all the way. We've beaten six Division Four teams this season and they have all been top teams which gives us a lot of confidence. Hopefully we can keep it going. With Ponty here , we're hoping to have very good support."
Division Four East side New Tredegar have kept their best form for the cup, and after two walkovers in the early rounds they defeated Abercarn 19-16 and Abertysswg 9-0. They then travelled to Hafodyrynys in round five where it needed a Ricky Hawkins try and two Craig Thomas penalties to edge through 11-10 against the Five East side.
The quarter-final paired them with Four South West side Resolven but three tries helped the Newts to a 22-17 victory and a meeting with Tycroes in the semi-final. Tycroes have had a good league season finishing in second spot but New Tredegar earned their visit to the Millennium Stadium with a 38-31 success.
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