The Ospreys under 16s booked their place in the final of the WRU Age Grade Championship courtesy of a bonus point victory over Blues North at Llandarcy.
Meanwhile it was heartache for Blues South who missed out on a place against the Scarlets although they won, again, at Tredegar, 19-15 against the Dragons.
A Gerin Eldred try for the Dragons left the South trailing 5-0 at the interval; but a rousing second half performance saw the visitors home, if only just.
James Benjamin bagged a second try for the Dragons with Ethan Davies converting and adding a penalty for good measure. However, when the South discovered the level of control that had taken them into contention going into the game, they crossed for the only time through prolific scorer Osian Davies.
Gareth Thompson, the side's leading scorer this season, converted the try and made sure that the South were at least in with a chance of reaching the last two, with three penalties and a drop goal.
John Richards, team manager at the Blues South, said; "We gave it our best shot and can be pleased with our effort this season.
"To the credit of the Dragons, they might not have had a place in the final to play for, but the threw everything at us. It was a strong game and very enjoyable."
Meanwhile the Ospreys booked their place in the final with coach David Jones' side running out comfortable 35-3 winners over Blues North.
Lewis Montague gave the North an early lead with a penalty before the Ospreys cut loose and scored five tries, including two from the second row Dewi Parry.
His first helped the hosts into a 7-3 interval lead and after crossing for a second 10 minutes into the second half, the Ospreys made sure of maximum spoils with further tries from Matthew Jenkins, Evan Yardley and Sam M Davies.
Outside half Sam Davies kicked five conversions to put the icing on a fine team performance.
The Scarlets, who went into their final game against the Dragons with a 100 per cent record, almost came unstuck as the visitors produced an outstanding display at Parc y Scarlets.
The Dragons dominated the first half and turned around six points to the good courtesy of two penalties.
After the interval, the Dragons maintained the intensity level, but ill discipline started to creep into their game. The Scarlets closed the gap with a try from scrum half Gareth George with Jordan Williams, who had already kicked a penalty, converting.
The Dragons again struck with a brace of penalties and an unconverted try, but the Scarlets made sure of a 17-17 draw thanks to a late try from Daniel Thomas that Williams converted from wide out.
The Under 16 Regional Championship final between the Ospreys and the Scarlets will take place at St Helens, Swansea at 7.15 on Wednesday 10 February. Tickets are £3 for adults, free entry for Under 16s. Spectators are kindly requested to enter St Helens via Bryn Road.
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