South Africa winger S'busiso Nkosi scored two tries as the Springboks edged Argentina 24-18 at Loftus Versfeld.
Elton Jantjies kicked four penalties and a conversion for a personal 14-point haul while Guido Petti Pagadizaval and Pablo Matera crossed the whitewash for the Pumas.
Joaquin Diaz Bonilla added a first-half penalty and conversion for Argentina, with Benjamin Urdapilleta scoring three points from the kicking tee in the second half.
Argentina claimed a 10-8 lead at the break after Petti's converted try on the stroke of half-time edged them ahead following Nkosi's first score and a Jantjies penalty.
The Springboks moved ahead thanks to Nkosi's second try in the 48th minute, converted by Jantjies, before Argentina levelled at 18-18 as Matera crossed.
Two more penalties from the Boks fly-half then sealed victory for Rassie Erasmus' side in the World Cup warm-up match.