Handre Pollard scored 31 points as the Springboks thrashed Argentina 46-13 to win the Rugby Championship for the first time.
The emphatic win gave the unbeaten Springboks a bonus point and a total of 12 points from their three matches, four more than second-placed Australia who earlier on Saturday stunned reigning champions New Zealand 47-26 in Perth.
Argentina collapsed in the second half after holding their own during the opening 40 minutes until a Pollard try gave South Africa an 11-point lead at the break. As Sanchez and Pollard traded a couple of penalties apiece, the scoreline became 13-14 with the half-hour mark approaching.
Flyhalf Pollard scored two of his side's five tries and kicked five penalties and three conversions for a personal haul of 31 points, his best in an global.
The Springboks' progress slowed early in the second half when scrumhalf Faf de Klerk was sin-binned, only for Pollard to cross again.
The Boks have never won the Championship and last won the southern hemisphere competition back in 2009 when it was still known as the Tri-Nations.
Duane Vermeulen will captain the team from the No.8 position, with former Sevens player Kwagga Smith retaining his place on the flank.
The hugely experienced prop comes into the side in Salta as Rassie Erasmus makes just three changes to the team that drew with New Zealand, all in the front row.
Kitshoff, Marx and Malherbe began the drawn Test away to World Cup trophy-holders New Zealand the following weekend.
"The Pumas are a very hard team to play at home and they will be fired up for this one in front of their passionate crowd in Salta", warned Erasmus. "It's one step up, still, a lot of work to be done but yah, it's a good feeling".
Traditionally a two-round competition, it has been reduced to a single round this year because the Rugby World Cup kicks off on September 20 in Japan.
"This Test is a good opportunity for Bongi and Trevor to start next to "Beast" [Mtawarira], who has a wealth of experience from playing more than 100 Tests for the Springboks".