The Springboks have dropped to fifth in the world rankings following their 37-25 loss to Argentina on Saturday.
Three consecutive Rugby Championship defeats have seen South Africa's rankings points total reduced from 86.37 to 84.37 points, which sees them fall behind Ireland, Australia and England in the pecking order.
After their 35-21 victory over Wales in Cardiff, Ireland have climbed to second place for the first time since the rankings introduction in 2003 and have cut the All Blacks' lead at the summit to 5.83 points.
The Wallabies gained 1.61 rating points to move on to 86.84, just 0.05 of a point behind Ireland and 1.44 ahead of fourth-placed England, the only top six side not in action at the weekend.
Meanwhile Argentina's historic win at Kings Park earned them two full rankings points. Los Pumas are now within 0.57 of a point of seventh-placed France.
World Rugby rankings (top 15):
1. New Zealand 92.72
2. Ireland 86.89
3. Australia 86.84
4. England 85.40
5. South Africa 84.37
6. Wales 82.94
7. France 79.74
8. Argentina 79.17
9. Fiji 77.04
10. Tonga 75.25
11. Samoa 75.14
12. Scotland 74.79
13. Georgia 72.16
14. Italy 71.85
15. Japan 71.15
Full rankings
How the rankings work
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