Paris - After their shock loss to Argentina, the Springboks are set to drop to No 5 on World Rugby's official rankings.
Ireland will move up to their highest ever spot on the world rankings due to be published by World Rugby on Monday.
They will move past the Springboks into the No 2 spot following a comfortable 35-21 win over Wales in a World Cup warm-up match in Cardiff on Saturday.
South Africa's shock 37-25 Rugby Championship defeat at home to Argentina - the Pumas' first ever success against the Springboks - was enough to see the Irish move up one place behind world champions New Zealand.
Australia will also climb two places to third after their victory in the Rugby Championship, secured with Saturday's 27-19 win over the All Blacks, giving them three victories from three.
The Springboks will drop three places to fifth - with England in fourth - having lost all three of their Rugby Championship matches.
Argentina's win will move them above France into seventh, while Wales will hold onto sixth despite their defeat.
World Rugby's rankings officially change on Mondays following weekend Test matches.