An inspired Nicolas Sanchez scored all of Argentina's points with a try, six penalties and a conversion, and the Pumas held off a fierce late onslaught from the All Blacks to secure a famous victory in their first test for more than a year.
The Argentinians were given almost no chance of registering a victory in their tournament opener after being kept off the pitch for almost the entire season by the global health crisis.
Flyhalf Sanchez was a clear Man of the Match but it was a team effort as the Pumas tackled like demons, rucked like bulls and ran the ball with confidence throughout the 80 minutes in front of 9,063 fans enjoying the late afternoon Sydney sun.
Ireland, Scotland draw South Africa at World Cup, England get Japan and Argentina
"It's a big game for Argentina rugby today," emotional captain Pablo Matera said on the pitch.
We're used to (adversity), it's always tough for Argentina. We just wanted to show our people that if you work hard, you get your rewards.
It was a most unlikely venue for their maiden win over the All Blacks but the ecstatic Pumas players gathered in front of a small band of their compatriots in the stands at the Western Sydney Stadium and celebrated with song and dance.
Captain Sam Cane finally forced his way over the Argentina line in the 53rd minute and winger Caleb Clarke followed after the hooter but it was too little, too late for the All Blacks.
"It was very tough, full credit to Argentina, they came out with more intent than we did and they thoroughly deserved their victory tonight," said Cane.
"They just kept coming."
Twice World Cup semi-finalists, Argentina have come close to beating New Zealand before. Even when they led 19-3 just after half-time, it only raised expectations of yet another great escape from the All Blacks.
Sanchez scored his team's only try after 19 minutes, getting a kindly bounce off his own chip kick before gathering to touch down as the referee was playing advantage after yet more ill-discipline from the All Blacks.
There was plenty of niggle and aggression from the Pumas as well but they kept their discipline when it counted and more importantly made remarkably few errors for a team with so little match practice.
"It's kind of surreal," said coach Mario Ledesma. "Just even playing that game after everything that has happened for Argentina this year.
"Some of the players have not seen their families for four months and they haven't complained once.
I think we'll remember this for a long time ... somebody will write a book about it.
Australia first as anthem sung in indigenous language before test
The Rugby Championship
All Blacks pay tribute to Diego Maradona before thrashing Pumas
Share this article