After three good performances had all ended in narrow defeats, Wales Under-19's crashed out by 49-0 to a fit and strong South Africa Schools team at Ellis Park, Johannesburg.
Played as a curtain-raiser to the South Africa-Australia Tri-Nations match, it was the home side who rose to the occasion.
Wales were behind at 8-0 when centre Stephen Ireland (Cardiff) was sin-binned for a tackle that also saw South Africa given a penalty try.
South Africa raced away in the second half to score 34 points without reply, though the Welsh pack battled hard to no avail.
Coach Dai Rees said afterwards: "South Africa is a notoriously difficult place to come to and win, but we asked for a tough itineray and that's what we got.
"We now know what a huge challenge we will have in the Junior World Cup next Easter."
A special video package as Pontypridd claimed the double for the first time in their history by winning the Principality Premiership final, including match build-up, highlights, post match reaction and dressing room celebrations.