A win for South Africa over arch-rivals New Zealand in Johannesburg on Saturday would leave the World Cup title-holders well placed to win the Rugby Championship a second time.
Bonus-point victories over Australia in Brisbane and Perth lifted the Springboks to 10 points, five more than second-placed New Zealand, who suffered a shock home defeat by Argentina.
New Zealand have dominated the annual southern hemisphere competition since its launch in 2012, winning nine editions with South Africa and Australia successful only once each.
AFP Sport presents five things to know before the 107th clash between the teams since they first met in 1921 in Dunedin, where New Zealand won.
ETZEBETH POISED
Veteran lock Eben Etzebeth will move within two appearances of the Springboks record of 127 held by former lock Victor Matfield if he plays off the bench.
The 32-year-old from the Sharks franchise in Durban currently shares second place with winger Bryan Habana.
Full-back Beauden Barrett will be the most capped starter for New Zealand having represented his country 128 times.
STADIUM STALEMATE
South Africa and New Zealand have won four tests each at Ellis Park since the dawn of the professional era in the mid-1990s.
The arch-rivals last met at the stadium on the outskirts of central Johannesburg two years ago with two late tries giving the visitors a 35-23 victory.
The average winning margin for the Springboks in their four triumphs was eight points compared with 8.25 points for the All Blacks.
MARX MENACE
Replacement hooker Malcolm Marx has scored 19 tries, predominantly from driving mauls, which is a record for a Springbok forward.
Two of those pushover scores came in Perth two weeks ago when South Africa completed a double in Australia with a 30-12 victory.
Bongi Mbonambi, the starting hooker on Saturday, has also benefited from the famed mauling of the record four-time world champions, claiming 14 test tries.
CAPACITY CROWD
South Africa have filled stadiums in Pretoria, Durban and Bloemfontein for their first three home fixtures this season, with 155 000 spectators watching the world champions.
The Johannesburg test is also a sell-out, with the 62 000 tickets snapped up in just over 30 minutes.
South Africa and New Zealand meet again on September 7 in Cape Town, with an official in the southwest city saying they could have filled the 60 000-seat venue four times.
FINAL SURVIVORS
Both South Africa and New Zealand will have 13 survivors from the 2023 Rugby World Cup final in the matchday 23s at Ellis Park.
South Africa have chosen 10 in the run-on XV with three on the bench while New Zealand went for an 11-two split between starters and replacements.
Handre Pollard slotted four penalties to give the Springboks a 12-11 victory over the All Blacks in the World Cup title decider at the Stade de France last October.