The Australians have booked their spot in the quarter-final with a 29-10 win over Argentina.
However, it has come at a cost with captain Henry Hutchison likely ruled out for the rest of the tournament - and likely even longer - with a knee injury.
Hutchison suffered the initial knock during the opening minute, getting leg strapped and soldiering on before collapsing in agony just after the break.
It was an eventual game for the Australian skipper, denying himself a try as he planted the ball on his foot and fell over the sidelines.
"I don't know but it's his knee. He looked pretty sore," coach John Manenti said on Hutchison's injury. "Unlikely for the rest of the weekend I think.
"He's a pretty tough bloke. At half-time, he said it was bothering him and wanted to keep going but he went one play and basically went down.
"He's been unbelievable for us and it's a real opportunity for other blokes to step up like Tim Clements to step up and take his opportunity."
For the third time in Sydney, the Aussies conceded the first points of the match when Marcos Moneta darted over.
In familiar territory, the hosts refused to panic and some great skill off the boot from James Turner delivered their first.
Whilst Hutchison should’ve had their second, Dietrich Roache made up for the effort just before the break to give them a 12-5 lead.
This kicked the Australian crowd into life and when Josh Turner and Maurice Longbottom scored in the corner, it sent them into overdrive.
"My family is sitting in the fifth row so I was just letting them know I love them dearly," Longbottom said on his celebration after the match.
"We've set ourselves nicely for the quarter-finals leading into tomorrow with a game to come."
Young gun Darcy Lancaster sealed the win off a great Roache offload, booking a date with France (9:03 pm AEDT).
“I think we built throughout the day,” Manenti added.
“Everyone was aware that game became must-win when probably at the start of the day we might’ve felt (the) Argies would beat GB and it was a matter of where we came.
“It became sudden death and off the back of that, the boys turned up and had a real good crack.”
Australia 29 (TRIES: James Turner, Josh Turner, Roache, Lancaster; CONS: Roache, Longbottom) def Argentina 10 (TRIES: Moneta, Pellandini)