The Wallabies did what they had to do to keep their World Cup hopes alive, defeating Portugal 34-14 in Saint Etienne.
They now need 'Os Lobos' to defeat Fiji by eight points or more next Monday (AEDT) to qualify for the quarter-finals.
The win was built off a strong first half thanks to three tries in the space of seven minutes.
Fraser McReight's try sealed the win after the break, although Portugal never stopped applying pressure on Eddie Jones' side.
Marika Koroibete got a well deserved try late as the Australians finish their group stages action on a high.
"We're still alive. That was the aim of the day," Jones said.
"For a young team down to 13 men we showed plenty of courage and fought hard. We've done that all season, sometimes the results haven't been in our favour...well, most of the time.
"It's a real credit to them. You look at the experience of our players out there, we're averaging less than 20 caps."
The Wallabies looked to tick over the scoreboard early but Portugal stunned them early with their frenetic style of play.
Their free-flowing style eventually found a way through as centre Pedro Bettencourt dives over untouched to the delight of the Saint Etienne crowd.
Bettencourt’s heroics were short-lived, with the centre sitting down for ten after a high tackle on Izaia Perese.
This allowed the Australians to settle the game and it was prop Angus Bell who delivered a brutal spell of play to settle the side.
It started with a great run off a lineout just inside Portugal’s 22, followed by Rob Valetini, popping the offload for Richie Arnold to score.
He then won a turnover that allowed Dave Porecki to barge over from a rolling maul, helped by a perfect kick from Ben Donaldson.
The loosehead finished it off with a barge over from close for his first try in gold to give Australia a commanding 24-7 lead by the time Bettencourt returned from the bin in the 26th minute.
Portugal nearly scored before the break, only to be stopped by a flying Andrew Kellaway bundling Nicolas Martins into touch.
Nawaqanitwase’s offload to Fraser McReight shortly after the break helped secure the all-important bonus point but the Australians didn’t make life easy for themselves.
They were reduced to 13 when Matt Faessler was sent for ten for a professional before Samu Kerevi followed him for a raised elbow in a carry, shades of Wales in 2019.
The Wallabies showed plenty of fight to hold out Portugal down two players, but the numbers caught up as Steevy Cerqueira scored at the back of the scrum.
Kerevi came back on the field with a point to prove, bursting the line with a great run.
It allowed winger Marika Koroibete to score a well earned try as the Australians closed out the game.
TRIES: Arnold, Porecki, Bell, McReight, Koroibete
CONS: Donaldson 3/5
PENS: Donaldson 1/2
TRIES: Bettencourt, Cerqueira
CONS: Marques 2/2
WALLABIES v PORTUGAL TEAMS
Australia (15-1): Andrew Kellaway; Mark Nawaqanitawase, Izaia Perese, Lalakai Foketi, Marika Koroibete; Ben Donaldson, Tate McDermott; Rob Valetini, Fraser McReight, Tom Hooper; Richie Arnold, Nick Frost; James Slipper, David Porecki (capt), Angus Bell
Replacements: Matt Faessler, Blake Schoupp, Pone Fa'amausili, Rob Leota, Josh Kemeny, Issak Fines-Leleiwasa, Samu Kerevi, Suli Vunivalu
Portugal (15-1): Nuno Sousa Guedes, Raffaele Storti, Pedro Bettencourt, Tomás Appleton (c), Rodrigo Marta, Jerónimo Portela, Samuel Marques, Thibault de Freitas, Nicolas Martins, David Wallis, Martim Belo, José Madeira, Diogo Hasse Ferreira, Mike Tadjer, David Costa
Replacements: Francisco Fernandes, Duarte Diniz, Francisco Bruno, Martim Belo, Steevy Cerqueira, Rafael Simões, João Belo, Joris Moura, Manuel Cardoso Pinto