IRELAND UNDER 21 36
WALES UNDER 21 38
Swansea star Gavin Henson gave a glimpse of why the IRB voted him the best young player in the world last year as he grabbed 18 points in a sensational victory for Wales at Donnybrook.
As the game moved into its final few moments it looked as though the sin-binning of Wales lock Bryn Griffiths after 60 minutes was going to prove the difference between two talented sides.
Wales led 20-13 at the interval and then 26-13 prior to the departure for 10 minutes of Griffiths.
But by the time the second row was let back onto the field he had seen his side concede 17 points and slip behind 30-26.
Wales should have scored with what everyone thought was the last move of the match, when they had a huge overlap, but they knocked on with the line at their mercy.
Then they stole the ball from the Irish scrum and Henson weaved his way over for their fifth try to steal victory from the jaws of defeat.
UC Cork flanker Denis Leamy grabbed two tries for the home side and UL Bohemians wing Martin McPhail got another.
The boot of Dungannon outside half Ian Humphreys, brother of Irish stand-off David Humphreys, did the rest of the damage with five penalties and three conversions.
But despite the 21 point contribution from Humphreys, it was the Welsh No 10 who stole the glory. Henson's try followed others from wings Liam Roberts and Nicky Jones, another from Rhys Williams and a penalty try.
SCORERS: Ireland Under 21: Tries: D Leamy 2, M McPHail; Cons: I Humphreys 3; Pens: I Humphreys 5. Wales Under 21: Tries: L Roberts, N Jones, R Williams, G Henson, penalty try; Cons: G Henson 2; Pens: G Henson 2; DG: G Henson.
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