Argentina and South Africa don't have a choice on Sunday.
To stay in the Rugby Championship race with New Zealand, the Pumas or Springboks must sweep both of their contests over the next two weeks, with the added burden of bonus points.
They are already five points off the pace after New Zealand's miracle win against Australia in Melbourne on Thursday. The All Blacks return home for the last round next week when they are fancied to collect a bonus-point win as they haven't lost at Eden Park since 1994, and to the Wallabies there since 1986. To make matters worse for the chasers, the All Blacks have the biggest points differential.
But that will matter more if the Rugby Championship is still on the line in the last match in Durban next week. First, Argentina and South Africa have to go through each other in Buenos Aires.
Form and history favour the Springboks, who looked more like themselves while pounding the Wallabies 24-8 in Sydney two weeks ago.
But the Pumas have no fear after home wins over the Boks in 2016 and 2018 and a historic run in this championship including a first win over the All Blacks in New Zealand, a record win over Australia, and leading the standings for the first time.
Pull off a win on Sunday and the Pumas will have toppled the Springboks, All Blacks and Wallabies in one championship for the first time.
"It will be very hard, but we have the tools to go out and look for the result," centre Jeronimo de la Fuente says.
He's returned to the side for the first time since he injured a thigh while scoring their third try against Australia in San Juan a month ago. De la Fuente has helped the Pumas reload to look much closer to the team which beat New Zealand in Christchurch than the one which lost heavily to the same New Zealand side a fortnight ago in Hamilton.
Also back are Nahuel Tetaz Chaparro, their most experienced prop, and former captain Agustin Creevy. If Creevy comes off the bench, he will become the sole holder of Argentina's test caps record, his 95th leaving behind Nicolas Sanchez, who was injured at the start of the test season.
The buildup has had hiccups.
Argentina relocated the match when the original stadium's field was declared unplayable after a weekend concert. The nearby Estadio Libertadores de Americas, hosting its first rugby test, is slightly smaller but a 48,000-seat sellout.
Undiminished is the fans' passion for Argentina's last home match of their first home season since 2019, which has produced that thrashing of Australia and a series win against Scotland.
South Africa forced home flyhalf Elton Jantjies and team dietician Zeenat Simjee after their alleged extramarital affair so as not to be a distraction.
Jantjies was in line to be a reserve. But South Africa kept faith in veteran utility Frans Steyn as the backup to third-string 10 Damian Willemse, who started the Sydney test at flyhalf for the first time and was man of the match. In fact, the starting XV is unchanged.
The world champion Springboks came to Buenos Aires straight from Sydney, and believe they have the confidence, the muscle and the talent to snuff out the Pumas' title challenge and rein in New Zealand's title hopes.
"If we play our best rugby," No. 8 Jasper Wiese says, "the bonus point is going to come by itself."
Argentina: Juan Cruz Mallia, Emiliano Boffelli, Jeronimo de la Fuente, Matias Orlando, Lucio Cinti, Santiago Carreras, Gonzalo Bertranou; Pablo Matera, Marcos Kremer, Juan Martin Gonzalez, Tomas Lavanini, Matias Alemanno, Eduardo Bello, Julian Montoya (captain), Nahuel Tetaz Chaparro.
Reserves: Agustin Creevy, Thomas Gallo, Joel Sclavi, Guido Petti, Rodrigo Bruni, Tomas Cubelli, Benjamin Urdapilleta, Matias Moroni.
South Africa: Willie le Roux, Canan Moodie, Jesse Kriel, Damian de Allende, Makazole Mapimpi, Damian Willemse, Jaden Hendrikse; Jasper Wiese, Franco Mostert, Siya Kolisi (captain), Lood de Jager, Eben Etzebeth, Frans Malherbe, Malcolm Marx, Steven Kitshoff.
Reserves: Deon Fourie, Ox Nche, Trevor Nyakane, Elrigh Louw, Kwagga Smith, Faf de Klerk, Andre Esterhuizen, Frans Steyn.
