South Africa 26-25 Argentina
South Africa struggled to get any momentum
Springboks fly-half Louis Koen denied Argentina a first-ever Test victory over South Africa by landing a penalty with the last kick of the game in Port Elizabeth.
The home side had struggled for long periods against the impressive Pumas who outscored their hosts three tries to two.
But Koen, who scored 16 points with a 100% return from six shots at goal, saved the 'Boks from defeat a fortnight before they open their Tri-Nations campaign.
It was another unconvincing display after two narrow wins over Scotland, whereas Argentina served further notice of their threat at October's World Cup.
Having beaten France twice at home in the last fortnight, they overturned an early 10-0 deficit to lead 15-13 at half-time through superbly-worked tries for centre Felipe Contepomi and wing Jose Maria Nunez Piossek.
Koen restored South Africa's lead after the interval only for
a Gonzalo Quesada penalty and a third try for Juan Martin Hernandez to put the visitors within sight of victory at 25-16 up.
S Africa 26 (13):
Tries: Coetzee, Russell
Cons: Koen 2
Pens: Koen 4
Argentina 25 (15):
Tries: Contepomi, Piossek, Hernandez
Cons: Quesada 2
Pens: Quesada 2
But the Springboks rallied with a try from replacement Brent Russell three minutes from time before Koen's injury-time penalty clinched an unlikely win.
South Africa had started brightly when hooker Danie Coetzee was bundled over for a try. Koen added the extras and then kicked a penalty.
But Argentina, who lost Rimas Alvarez to the sin-bin, took the lead in a dazzling five-minute spell around the half-hour.
Quesada got the Pumas on the board with a penalty before impressive driving and handling yielded two quick-fire tries.
Contepomi finished off a rampaging length-of-the-field move after 29 minutes, in which the ball moved through a dozen pairs of hands.
Quesada missed the conversion, but added the extras three minutes later when right-wing Piossek cantered over after great work from flankers Rolando Martin and Lucas Ostiglia.
Argentina held their own in all areas
South Africa were grateful for a Koen penalty with the last kick of the half to keep them within striking distance, and he dutifully restored the home side's lead 11 minutes into the second half.
But Quesada swiftly replied with a penalty of his own, and Argentina continued to look the greater attacking threat.
Another try for Contepomi - who intercepted Gcobani Bobo's pass to race 50m to the line - was controversially disallowed when Alvarez was penalised for a scuffle on the floor with Springboks captain Corne Krige.
But a third score from Hernandez, after Piossek had beaten three tacklers, appeared to have sealed victory.
Russell though - on as a late replacement - sniped his way over, Koen converting, before Pedrie Wannenburg's late charge and Koen's winning kick completed the salvage job.
South Africa: van der Westhuyzen; Terblanche, Joubert, Bobo, Rossouw; Koen, Davidson; Kempson, Coetzee, Visagie, Davids, Matfield, Krige, Venter, Wannenburg.
Replacements: Bands, Sephaka, Boome, Skinstad, van der Westhuizen, Halstead, Russell.
Argentina: Martin Hernandez; Nunez Piossek, Orengo, Contepomi, Albanese; Quesada, N Fernandez Miranda; Grau, Ledesma, Reggiardo, Fernandez Lobbe, Alvarez, Martin, Ostiglia, Longo Elia.
Replacements: Mendez, Bonorino, Albacete, Phelan, Albina, Senillosa, Stortoni.
Referee: Nigel Williams (Wales)