Mendoza — Australia scored 17 unanswered points in the last quarter of the match to beat Argentina 37-20 on Saturday in the final game of the Rugby Championship.
Scrumhalf Will Genia and winger Reece Hodge scored late tries as the Wallabies pulled away to snuff out any chance of another Argentine comeback after the Pumas had clawed their way back to 20-20.
The result enabled Australia to leapfrog SA and finish as runners-up to New Zealand in the final championship standings with two wins, two draws and two losses for 15 points.
Argentina finished bottom after losing all six championship matches and failing to secure any bonus points for the first time since joining the competition in 2012.
Australia triumphed despite a mixed kicking performance from star flyhalf Bernard Foley. He slotted his first attempt, then fluffed four in a row before regaining his composure and nailing the next four for a 17-point personal tally that included a try.
It lifted his championship total this season to 80 points, making him the leading individual scorer ahead of New Zealander Beauden Barrett and South African Elton Jantjies.
Foley opened the scoring at the 40,000-capacity Estadio Malvinas Argentinas by slotting a close-range penalty on 15 minutes. Australia increased their lead to 8-0 when winger Marika Koroibete raced over for his third try in two Tests before Argentina hit back with a try from lock Matias Alemanno.
Flyhalf Nicolas Sanchez landed a conversion and added a penalty to briefly put the Pumas in front.
Genia threw a long pass from a maul and Hodge darted over unchallenged as the Wallabies regained the lead but a late Sanchez penalty tied the scores at 13-13 at half-time.
Foley converted his own try 13 minutes into the second half but the Pumas again got back on level terms, with centre Santiago Gonzalez Iglesias scoring a converted touchdown.
The Wallabies steadily began to dominate territory and possession, opening up cracks in the Argentine defence.
Genia scored just past the hour and Foley converted then added a penalty after Argentine lock Marcos Kremer was yellow-carded for a dangerous tackle. Hodge then went over after a brilliant pass by replacement centre Samu Kerevi just before being bundled into touch and the Foley conversion wrapped up a convincing triumph.