Argentina won 23-19 for a deserved victory against an error-prone Australia at Cbus Super Stadium on the Gold Coast.
After a free-flowing first half with 2 tries each, Argentina's penalty goal accuracy won the game for them, with Boffelli and Sanchez scoring.
A 59-metre Reece Hodge attempt with 25 minutes to go, fell just short and in the end proved the difference.
Israel Folau nearly saved the day for the Wallabies in the last moments of the game, but rather than passing to Bernard Foley, he was stopped in his tracks by a crunching tackle from Lavanini just metres from the line.
Instead the Pumas won for the first time in Australia since 1983 and broke a 6-match losing streak against the Wallabies.
South Africa's shock defeat of the All Blacks in Wellington means that the Wallabies are in last place in the Rugby Championship after 4 matches played.