Replacement fly-half Billy McBryde kicked a late winning penalty as Wales Under-20 fought back from 15-5 down to beat Scotland Under-20.
Rory Hutchinson’s penalty and tries from Matt Smith and Murray McCallum built the visitors’ lead.
Shaun Evans struck back between Scotland’s tries.
And after Tom Phillips and Keelan Giles went over, McBryde – son of Wales forwards coach Robin – added the winning touch.
Robin McBryde played hooker for Wales and toured Australia with the 2001 British and Irish Lions under Graham Henry.
Wales U20: Rhun Williams (RGC); Elis-Wyn Benham (Cardiff Blues), Joe Thomas (Ospreys), Harri Millard (Cardiff Blues), Keelan Giles (Ospreys); Dan Jones (Scarlets), Reuben Morgan-Williams (Ospreys); Corey Domachowski (Cardiff Blues), Dafydd Hughes (Scarlets), Dillon Lewis (Cardiff Blues), Shane Lewis-Hughes (Cardiff Blues), Bryce Morgan (Newport Gwent Dragons), Tom Phillips (capt, Scarlets), Shaun Evans (Scarlets), Harrison Keddie (Newport Gwent Dragons).
Replacements: Ifan Phillips (Scarlets), Robert Lewis (Cardiff Blues), Leon Brown (Newport Gwent Dragons), James Ratti (Ospreys), Morgan Sieniawski (Cardiff Blues), Declan Smith (Scarlets), Billy McBryde (Scarlets), Joe Gage (Ospreys).
Scotland U20: Ruairi Howarth; Robbie Nairn, George Taylor, Tom Galbraith, Darcy Graham; Rory Hutchinson, Hugh Fraser; Murray McCallum, Jake Kerr, Callum Sheldon, Callum Hunter-Hill, Scott Cummings, Andrew Davidson, Matt Smith, Ally Miller.
Replacements: Lewis Anderson, George Thornton, Adam Nicol, Stephen Ainslie, Scott Burnside, Charlie Shiel, Chris Lines, Ben Robbins.