With a nine-wicket victory against India in the third Test at Indore, Australia guaranteed their spot in the World Test Championship championship match in June.
Travis Head scored 49 runs without being out, while Marnus Labuschagne added an unbeaten 28 as the tourists clinched the game on day three before lunch.
Usman Khawaja was caught behind the second ball, but Head and Labuschagne put up a 78-run stand that was unbroken to get them home.
In The Oval in London, they will compete against either India or Sri Lanka.
India will be guaranteed a spot if they defeat Australia in the series’ fourth and final Test, which begins on March 9 in Ahmedabad.
The two-Test series between Sri Lanka and New Zealand, which begins at 22:00 GMT on March 8, will be decided by a draw or loss and a 2-0 Sri Lanka victory.
Between June 7 and June 11, the World Test Championship final will be played, taking place one week before to the first Ashes Test at Edgbaston between Australia and England.
India has a 2-1 advantage in the four-Test series following two decisive victories.
After bowling India out for 109 on the first day of the third Test, Australia took control and eventually built an 88-run advantage in the first innings.
Then, in the second innings, off-spinner Nathan Lyon took 8-64 to give his team a simple chase.
“That was a full performance in the end,” remarked Steve Smith, who was leading Australia alongside Pat Cummins, who was in Australia with his unwell mother.
“We’re extremely delighted to have qualified for the championship game, but for us, it all comes down to playing excellent cricket.
“Maybe we can put up a similar performance and finish the series really successfully. We’ve fought back here and played our style for longer periods of time than we did in the previous two Tests.”
It has been a very extraordinary Test series, but to come out and put in a really strong team effort is something I really proud am of, said Lyon, who has now claimed a record 113 wickets in Test matches against India.
Rohit Sharma, the India captain, said: “We need to refocus and figure out what we did correctly in the first two Test matches. Regardless of the pitch conditions, you have to show up and perform your duties.
“On difficult pitches, you must be brave.”