South Africa enter the third Test against New Zealand in Soweto with a 0.54-point lead over the All Blacks in the World Rankings. A Springbok win by more than 15 points would stretch that gap to 3.38 points.
New Zealand, for their part, would reclaim top spot with a victory — and would, in doing so, create a piece of rankings history: three consecutive weeks in which the No.1 ranking has changed hands.
Elsewhere this weekend, a win for Argentina over Australia would see the Pumas recover the seventh place they surrendered after last weekend's defeat in Jujuy. Australia need a winning margin of more than 15 points to leapfrog Scotland into sixth.
In Niigata, Japan host Canada with no rating gain possible for the hosts regardless of result, given the 14.99-point gap between the sides. Canada sit 24th and can rise to 22nd with a draw, or climb above Romania into 21st with a win by more than 15 points.