Argentina beat Wales in an 11-try spectacular in Tucuman on Saturday.
Tries: F Contepomi, M Contepomi, Borges 2, Gaitan, Longo
Cons: F Contepomi 4
Pens: F Contepomi 4
Tries: Parker, Peel, Forster, Charvis, Luscombe
Cons: Henson 5
Pens: Henson 3
The hosts only led 19-9 at the break but the game exploded into life with 10 tries in the second half.
The Pumas scored six tries through Lucas Borges (2), Gonzalo Longo, Martin Gaitan, Manuel Contepomi and his twin Felipe, who also kicked 20 points.
Dwayne Peel, Jason Forster, Colin Charvis, Sonny Parker and Hal Luscombe scored Wales' tries, with Gavin Henson adding 19 points with the boot.
Mike Ruddock started his reign as Wales coach with a hugely encouraging 42-0 over the Barbarians last month, but his side looked all at sea against an under-strength Argentina side.
The match was effectively lost in a devastating 15 minute spell after the interval where the hosts crossed for four tries.
And the ease with which the Argentines breezed past a disorganised and lethargic Wales defence will give Ruddock most cause for concern.
There was a degree of controversy in the opening score when the video referee judged that Longo had grounded the ball despite Ceri Sweeney's desperate tackle, but any similar defensive aggression was sorely missed in the second half.
Borges' two tries resulted from poor Welsh re-starts, and Felipe Contepomi added another in no time as Wales, not for the first time, lost the ball in possession.
At 38-9, the game already appeared out of Wales' reach, but a 51st-minute try from scrum-half Dwayne Peel gave Wales hope.
In keeping with the shocking level of defence, Peel was able to dance past half a dozen ponderous Puma forwards to score from a quickly taken tap penalty.
Less than four minutes later, Argentina scored their fifth try as centre Martin Gaitan finds a huge hole in the Welsh backline.
The game now resembled a sevens match rather than a Test match, and former Wales sevens captain Forster grabbed a try to celebrate his first cap.
But back came the hosts, with centre Manuel Contepomi scored what proved to be the decisive try with 15 minutes left.
Gareth Llewellyn made a record breaking 88th appearance for Wales
Defeat would have been harsh on the Pumas, but they almost succeeded in throwing away an almost unassailable lead.
Wales captain Charvis, who was harshly sin-binned in the first half, kept his side's hopes of a comeback alive with 69th minute try, and Parker crossed some five minute later to reduce the deficit to just 13 points.
And when Luscombe finished off a period of sustained possession to score a fifth try under the posts in injury time, Wales sensed the opportunity for a remarkable victory.
There was still time for one final attack, and a try looked a distinct possibility as Shane Williams broke the first line of defence deep inside his own half.
He threw an inviting inside pass to Parker, but the centre clumsily knocked on to let Argentina off the hook.
Argentina: H Senillosa, L Borges, M Gaitan, M Contepomi, J Piossek, F Contepomi, M Albina, R Roncero, F Mendez, O Hasan, P Albacete, I Lobbe, M Durand, L Ostiglia, G Longo (capt).
Replacements: E Ginzau, P Cardinali, P Bouza, M Shusterman, L Fleming, G
Bustos, J Orengo.
Wales: R Williams (Blues), H Luscombe (Dragons), S Parker (Ospreys), G Henson (Ospreys), S Williams (Ospreys), C Sweeney (Dragons), D Peel (Scarlets), D Jones (Ospreys), M Davies (unattached), A Jones (Ospreys), B Cockbain (Ospreys), G Llewellyn (Ospreys), C Charvis (Newcastle, capt), J Forster (Dragons), M Owen (Dragons).
Replacements: H Bennett (Ospreys), G Jenkins (Blues), D Morris (Leicester), J Thomas (Ospreys), M Phillips (Scarlets), N Robinson (Blues), T Shanklin (Blues).
Referee: Donal Courtney (Ireland).