Caltex Socceroos midfielder Jackson Irvine believes automatic qualification for the World Cup is still within reach despite Thursday's defeat in Saitama.
READ: Japan v Caltex Socceroos: how the game unfolded
Australia slipped to their first loss in Group B as goals from Takuma Asano and Yosuke Ideguchi confirmed Japan's place at Russia 2018.
While the Blue Samurai are out of reach and are now qualified for Russia 2018, Ange Postecoglou's side remain level on 16 points with second-placed Saudi Arabia.
And with the top two to play each other in the final match day, Australia will remain a chance to leapfrog the Green Falcons by defeating Thailand in Melbourne on Tuesday night by enough to go through.
NOT FINISHED YET
"It's not finished yet," Irvine said after the match.
"While the disappointment is still raw, we will go to Melbourne and stick to our guns and try to score some goals that will get us to the World Cup.
"It's going to be difficult now but as long as it's mathematically still possible we will be giving it everything we've got."
The Caltex Socceroos dominated possession at Saitama Stadium and came close to open the scoring when Mathew Leckie hit the post, only for Asano to strike shortly before the interval.
Ideguchi added a classy second with around 10 minutes remaining to cap the hosts' clinical victory.
"They [Japan] sat deep and made it very difficult for us to break them down with our passing," Irvine said.
"They were waiting for turnovers and transition moments and they were very effective at doing that."