It is only Argentina's second year in the four-nation, southern hemisphere championship but already they have shown their competitive capability against the Springboks, New Zealand and Australia.
South Africa had to scramble for a draw with Argentina last year away in Mendoza and expect the powerful visiting pack, plus their strength at the breakdown, to be a major challenge again.
"The positive for us is that we know what to expect now," South Africa's second-year coach Heyneke Meyer said this week. "Last year we didn't really know what to expect in the first game."
Saturday's match at the 94,700-seater complex in Soweto (1300 GMT) is the main feature of a double bill, also including a football international, to honour former President Nelson Mandela.
Meyer has stuck with the young backline that impressed in three home internationals in June but said the Rugby Championship would be a big step up from the matches against Italy, Scotland and Samoa.
"The main difference in the Rugby Championship is that teams are better, defences are better organised and you don't get as many chances," Meyer added.
"You can sometimes play better rugby but lose the game because the other team gets one opportunity and they take their chances."
With just two starting line-up changes from the last international in June, Meyer has stuck with a promise for more consistent team selection and resisted the urge to start with recalled scrumhalf Fourie du Preez.
However, the 31-year-old is expected to get a run off the bench for his first cap since the 2011 World Cup.
Duane Vermeulen takes over at number eight from the injured Pierre Spies while Juandre Kruger is restored at lock.
Felipe Contepomi will lead Argentina in place of injured captain Juan Martin Fernandez Lobbe, retaining the role he played in June when an under-strength side lost two home tests to England.
Argentina have restored the vast majority of the team rested for those matches after an intensive month-long training camp in the United States ahead of the Rugby Championship.
"The goal for this tournament is the same as last year, continue to grow and learn to be better players to be properly prepared for the 2015 World Cup," fullback Juan Martin Hernandez said on arrival in South Africa this week.
South Africa, ranked second in the world behind New Zealand, have won 14 of their 15 previous tests against Argentina, who are 10th in the IRB rankings.
Teams:
South Africa - 15-Willie le Roux, 14-Bryan Habana, 13-JJ Engelbrecht, 12-Jean de Villiers (captain), 11-Bjorn Basson, 10-Morné Steyn, 9-Ruan Pienaar, 8-Duane Vermeulen, 7-Willem Alberts, 6-Francois Louw, 5-Juandré Kruger, 4-Eben Etzebeth, 3-Jannie du Plessis, 2-Adriaan Strauss, 1-Tendai Mtawarira.
Replacements: 16-Bismarck du Plessis, 17-Gurthrö Steenkamp, 18-Coenie Oosthuizen, 19-Flip van der Merwe, 20-Siya Kolisi, 21-Fourie du Preez, 22-Pat Lambie, 23-Jan Serfontein.
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Argentina - 15-Juan Martin Hernandez, 14-Gonzalo Camacho, 13-Marcelo Bosch, 12-Felipe Contepomi (captain), 11-Juan Imhoff, 10-Nicolas Sanchez, 9-Martin Landajo; 8-Leonardo Senatore, 7-Juan Manuel Leguizamon, 6-Pablo Matera, 5-Patricio Albacete, 4- Manuel Carizza, 3-Matias Diaz, 2-Eusebio Guinazu, 1-Juan Figallo
Replacements: 16-Agustin Creevy, 17-Nahuel Lobo, 18-Juan Pablo Orlandi, 19-Mariano Galarza, 20-Julio Farias Cabello, 21-Tomas Cubelli, 22-Santiago Fernandez, 23-Horacio Agulla
Referee: Chris Pollock (New Zealand)
(Editing by Peter Rutherford)
