A gutsy Argentina stunned the All Blacks 25-15 Saturday to pull off one of rugby's biggest upsets, consigning an embarrassed New Zealand to their first back-to-back defeats in almost a decade.

Fly-half Nicolas Sanchez scored all the Pumas' points to hand them their maiden victory over the rugby powerhouse in the 30 Tests they have played.

Mario Ledesma's side were given virtually no chance ahead of the Tri Nations match in Sydney after a coronavirus-hindered build up of only two low-key practice games.

But in their first Test since the World Cup last year, they pulled off a miracle.

It was a humiliating defeat for New Zealand who were shocked 24-22 by the Wallabies in Brisbane last week and have now lost back-to-back Tests for the first time since 2011 when they crashed to South Africa and Australia.

Coach Ian Foster axed 10 players and named what many regarded as the All Blacks' best run-on side after last week's game, but they were no match for a Pumas team helped by former Australian coach Michael Cheika.

Unlike Australia and New Zealand, Argentina did not have a Super Rugby competition to help them prepare. But after months of quarantine, they were chomping at the bit and took their frustrations out on a sloppy All Blacks in a dominant first-half.

With New Zealand struggling to create chances with poor kicking, ill-discipline and too many errors, they incredibly went to the break 16-3 in front.

New Zealand staged a second-half fightback, but with their eyes on a major upset, Argentina grimly resisted intense pressure to post their best-ever result.

Argentina got the first points on the board in the fifth minute with Sanchez nailing a penalty from the half-way line after some push and shove instigated by New Zealand's Shannon Frizell.

It didn't take long for Richie Mo'unga to level the scores but Argentina were playing well, stringing together plenty of phases.

Their pressure culminated in dangerman Sanchez crossing for the first try of the game, getting on the end of his own chip kick to touch down under the posts.

He converted to give his side an unlikely lead which they stretched to 13-3 when Sanchez drilled another penalty, with Jordie Barrett the offender.

Only a try-saving tackle from Aaron Smith prevented the Pumas going further in front after Tomas Cubelli broke free, but more All Blacks ill-discipline handed them another penalty which the laser-like Sanchez again put over.

It sent them to the break with a comfortable lead, leaving New Zealand with a major task to save their blushes.

That only got harder when the boot of the irrepressible Sanchez earned Argentina another three points soon after the restart.

With their reputation on the line, New Zealand finally woke up and skipper Sam Cane crashed over for their opening try on 52 minutes after a nicely worked rolling maul from a lineout.

Mo'unga converted only for Sanchez to move the Pumas back into a 12-point lead with another successful penalty.

New Zealand began applying heavy pressure and Caleb Clarke scored a late try, but the Argentinian defence had done enough to ensure a famous win.

Picture: Argentina pulled off a miracle in their first Test since the World Cup last year (David Gray via MSN)