The Indonesians slipped from third to fourth in Asian Group C with three matches remaining, four points off the second place that offers automatic progression to the finals along with already qualified Japan. 

Even if finishing third or fourth offers passage to the finals via another round of Asian qualifying, Tuesday's clash with fifth-placed Bahrain in Jakarta looms as a must-win game.

"The positive thing is that we kept on going, and the spirit in the team will always be there," Kluivert told reporters.

"You guys don't see the spirit that we have in the team. We will react absolutely against Bahrain. 

"But now we have to digest first this defeat. We will analyse everything and prepare ourselves for Bahrain, we can't do more than that." 

Despite Thursday's lop-sided scoreline, Indonesia dominated large parts of the game with their high-pressing style and Kluivert was convinced the result would have been different had Kevin Diks not missed a seventh-minute penalty. 

"Of course, that's my playing style, and I think that from the beginning, we had a grip on the game," the former Netherlands and Barcelona striker said. 

"I think that we played better than Australia. But it just shows how important it is to make a penalty or not. What it does mentally, is a big thing."

Kluivert can also take solace from the fact that last time Indonesia suffered a heavy defeat -- 4-0 to Japan last November -- they rallied to stun Saudi Arabia 2-0 five days later. 

"It will be a very difficult game again," Kluivert said. "First of all, the most important thing is to get the minds back together, give them the positive energy. 

"We need to get our get our heads together, get the positivity back in the group, and try to get a good result. We need to have a good result against Bahrain at home."

Australia now have 10 points, four clear of Indonesia, with three games to play, including a crunch away fixture against China on Tuesday.

Saudi Arabia and China, who meet later in Riyadh, both have six points, as do Bahrain who clash with Japan in Saitama. Japan will book their place at the World Cup if they win.

Just the top two progress automatically, with third and fourth forced into another round of Asian qualifying.

Defeat reinforced the scale of the task facing former Barcelona forward Kluivert, who was appointed in January after South Korea's Shin Tae-yong was sacked.

His side head home for a must-win showdown against Bahrain next week in their bid to reach the World Cup for the first time since independence in 1945.

Australia were without a handful of injured regulars, including Leicester defender Harry Souttar and Middlesbrough midfielder Riley McGree.

But they still got the job done against a team featuring 10 players born in the Netherlands and naturalised to play for Indonesia.