Wales' hopes of securing a top-four seeding in the 2015 World Cup nosedived after Argentina stunned them at the Millennium Stadium.
Eleven years to the day following Argentina's only previous victory over Wales in Cardiff, second-half tries from wings Juan Imhoff and Gonzalo Camacho left the reigning RBS 6 Nations champions reeling.
And to make matters worse, Wales also suffered a double injury blow when centre Jamie Roberts and lock Alun-Wyn Jones departed inside the opening 40 minutes.
Full-back Leigh Halfpenny kicked all Wales' points, but they were outplayed by a Pumas team battle-hardened from recent home and away appointments with New Zealand, Australia and South Africa in the southern hemisphere's inaugural Rugby Championship.
Fly-half Nicolas Sanchez weighed in with two drop-goals, two conversions and a penalty, while veteran centre Felipe Contepomi kicked a penalty before he was forced off injured after just 10 minutes.