The Blitzboks secured a 33-12 win against the South American side who finished in the top four in last weekend's tournament in Las Vegas.
Argentina scored straight from the kick-off when they got hold of the ball and Fernando Luna raced through to shock the South Africans into action.
First Justin Geduld rounded off a strong run from JC Pretorius before a yellow-card against Argentina turned the match upside down.
Springbok Sevens captain, Philip Snyman, was cleaned out at a ruck illegally and the culprit was send to the side of the field.
The Blitzboks were very clinical in the two minutes they had the numerical advantage.
Two tries by Siviwe Soyizwapi on either side of the halftime whistle gave South Africa a 14-7 lead at the break and a 19-7 one just after play resumed.
Muller du Plessis and Stedman Gans also scored tries as the South Africans cut loose on attack.
A late try by Argentina gave them some respite, but the match was won by South Africa long before then.
"We needed to stay compose after they scored in the first 30 seconds and we managed to do so. We recovered nicely," said Kok, who is playing in his 43rd tournament in the World Series.
Tries: Justin Geduld, Siviwe Soyizwapi (2), Muller du Plessis, Stedman Gans. Conversions: Branco du Preez, Selvyn Davids (3).