A 2-1 victory over Thailand in Melbourne put the Socceroos in second spot in Group B three points ahead of Saudi Arabia.
Group leaders Japan have already qualified for Russia 2018.
The Saudis would seal direct qualification for the finals with victory over Japan early Wednesday (AEST) on the basis of a better goal difference.
Anything but a victory for the Saudis would give the Australians direct access.
Ange Postecoglou’s Socceroos played one of their best matches in this rollercoaster campaign, maintaining a high tempo throughout and creating enough scoring opportunities to win three games.
This might suggest that there is not too much wrong after all with the three-at-the-back formation the coach introduced with mixed effect in the last six months.
Other than the fact that expecting players to adjust to a new system midway through a tough World Cup qualifying campaign was always going to be asking a bit too much.
One prevalent problem with this Socceroos team, however, is that they seem to be always vulnerable to the quick counter-attack regardless of who plays and which system they use.
The Australians concede most of their goals after losing the ball up field and when fast forwards get behind the last line of defence.
It was more of the same against Thailand.
The plucky Thais were under the gun for most of the match and they would be happy to leave Melbourne with just a one-goal defeat. Such was Australia’s territorial and tactical domination.
Three times the Socceroos hit the woodwork and on other occasions they were foiled by inspired goalkeeping and desperate goal-line clearances.
How Tom Rogic did not get on the scoresheet he will never know.
The Thais however in their fewer attacks exposed Australia’s slow defence three times.
And it was on one of these occasions late in the second half that they scored a marvellously worked out equaliser.
The Australians now have to wait for the result of the last group match in Jeddah to find out if they are going through to the World Cup directly.
If the Saudis beat Japan the Australians’ worst fears will be realised and they will have to negotiate two playoffs in the space of a few weeks to get through to Russia via the back door.
First up would be a playoff against the third-placed team in Asia’s other group and if successful the Socceroos would have to beat the fourth-placed team in CONCACAF.
It certainly is not the scenario we expected when the qualifying campaign kicked off more than two years ago.