The Springboks built on an encouraging first half in which they held a 21-9 lead over Los Pumas at the Nelson Mandela Bay Stadium to outscore the visitors three tries to none for the 32-12 win.
This followed on a triumphant Castle Lager Lions Series last week in which they clinched a two-one series win in Cape Town.
Jantjies was in fine form and slotted five penalty goals and a conversion to keep the score-board ticking over, while Wiese was named Man of the Match after a stellar performance in the No 8 jersey.
“It was massive for us to get the result and a bonus point in the first match,” said Jantjies.
“Argentina are a well-coached team, and they play with a lot of emotion.
“We knew what their plan was, and they tried to implement it throughout the match, but we did well to implement our plan and to get the result as well.”
The experienced flyhalf added: “It was also good to see a few guys get a chance to play, and players like Joseph (Dweba, hooker) and Jaden (Hendrikse, scrumhalf) making their debuts.
“This is a special team when it comes to preparation for a match, whether one plays or doesn’t. Everyone works together as a team.”
Jantjies said another notable trait about the squad was the ability to switch on mentally for big occasions – as they did this week after their triumphant Castle Lager Lions Series campaign.
“It was a privilege to win such a big series against the British & Irish Lions and then to have a chance to play in the Rugby Championship,” said Jantjies.
“We celebrated (winning against the British & Irish Lions) last week Saturday, and from Sunday it was about recovery and preparing for this match.
“The preparation this week was great, and it showed the in standards set that everyone was switched on.”