The number one ranking is on the line for the third consecutive weekend when South Africa host New Zealand at FNB Stadium in Soweto on Saturday, with the Springboks holding a razor-thin 0.54-point advantage over the All Blacks heading into the decider.
The lead has already swapped twice in as many weeks — New Zealand took top spot after winning the first Test at Ellis Park, only for the Springboks to reclaim it with victory in Cape Town. Should the All Blacks complete a 2-1 series win in Soweto, it will mark the first time since the rankings were introduced in October 2003 that the number one position has changed hands in three successive weeks.
New Zealand have won on their two previous visits to FNB Stadium — 29-22 in 2010 and 32-16 in 2012 — and a win of any margin on Saturday would hand them top spot regardless of the scoreline. A Springbok win by 15 points or fewer extends their lead to 2.43 rating points; a win by more than 15 pushes that cushion to 3.38. A New Zealand win by more than 15 points would give them a 2.62-point buffer at the summit. A draw leaves South Africa in first place but costs them 0.05 rating points. Neither side can finish the weekend outside the top two.
Elsewhere in the Rugby Championship, Los Pumas host Australia in Mendoza with seventh place at stake. Argentina, who slipped below the Wallabies after last weekend's defeat in Jujuy, need a win to reclaim that position — a draw is insufficient. Australia can leapfrog Scotland into sixth only with a win of more than 15 points. Neither side can drop below eighth.
In Niigata, Japan host 24th-ranked Canada, though the 14.99-point ratings gap means Japan cannot improve their standing regardless of the result. A draw lifts Canada two places to 22nd, while a Canadian win by more than 15 points would move them above Romania into 21st — their highest ranking since September 2024 and Romania's lowest since the system launched. A Japanese win, by any margin, drops them a place to 13th with Georgia the beneficiaries.