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."
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.