Pumas scored seven tries in biggest winning margin and points tally against the Welsh.
Wales scored four tries with scrum-half Tomos Williams and hooker Dewi Lake going over in the first half and flanker Jac Morgan and full-back Blair Murray after the break.
Wales hold out a driving lineout thanks in no small part to intelligent play from captain Jac Morgan who got right in the middle of the Argentina maul.
Tomos Williams and Josh Adams combine to send Wales 70 metres upfield.
The scrum-half hoofs a quick drop-out up field and Adams shows he has lost none of his pace over the years as he chases down Santiago Carreras to win a scrum mid-way into Argentina's half.
Converted try: Wales 0-7 Argentinapublished at 7 mins
7 mins
Delgado try, Carreras con
It does!
Wales rebuff the first couple of goes but the big-tight-head is hard to stop from a metre out - even with Jac Morgan trying to wriggle his body under the ball.
Mateo Carreras gives Wales an early warning of his pace but Blair Murray returns the compliment, hacking the ball back up field to set the hosts an early attacking chance.