And with a new level of competitive tension and preparation behind them, they feel more steeled than ever to make that happen.
Players have been in camp for up to eight weeks, via a pre-tournament camp in Sarasota that started on May 3 which should hold them in good stead for a trip to sweltering Dallas.
Defender Aziz Behich, at his third World Cup, has watched the belief build as Australia prepare to face Egypt in the round of 32 in Arlington on Friday (Saturday AEST).
"When you get 26 Australian boys together, that belief goes through the roof, and it's been no different from the beginning in Sarasota," Behich said.
"We knew what we wanted to accomplish and the first step was getting out of the group stages - and we managed to do that.
"And now, obviously, now it's game by game, it's knockout football, it's a lot different to what it was. But the boys know that, and (are) full of energy and excitement.
"... We're a tight-knit group. We work hard for each other, we go to battle for each other.
"Our foundation was set long ago and it's no surprises for us within these four walls, the way we can grind out every game at a very high level."
The competitiveness within the squad has also steeled it.
Socceroos coach Tony Popovic has been unapologetic and bold in his team selections.
Behich, 35, and Jackson Irvine didn't start the first two games while skipper Maty Ryan hasn't played a minute, with Patrick Beach preferred in goal.
Behich was Jordan Bos's understudy in the first two group games.
The 35-year-old started against Paraguay at left wing-back, with Bos irrepressible on the right after Jacob Italiano's tournament-ending groin injury - and wants to keep his spot.
"I came here to play," Behich said.
"I'm experienced enough to know that when things don't go your way, you can't just throw in the towel.
"I've just had my head down working, because in a campaign like this, I always say everyone's needed within the squad - and obviously the squads are bigger now - but everyone plays a part.
"It's a group effort, whether they're playing or not playing, because we push each other every day at training and we're all striving for the same thing."
Popovic's post-Paraguay message to the players was clear: enjoy the moment, then focus on recovery and beyond.
"The mentality has to stay the same - and that's to go out and train hard, and everyone's going to press their claims, because everyone wants to play again," Behich said.
"So that's why I think our level in games have been so high, because we almost train the way we play. That's the way the boss has set the standards, and we just follow."
Australia will train in Oakland until Tuesday then fly to Dallas on Wednesday, where temperatures are forecast to hit 35 degrees - a solid 10-15 more than the Bay Area.
"We have to respect that. We have to take that into consideration," assistant Hayden Foxe said on Saturday.
"The beauty of the one (stadium) in Dallas is that it's indoors, it's air-conditioned, so it's going to be very similar temperatures to here.
"So we're lucky with the temperatures that we're training at.
"Now it's just a matter of the time frames and all the small details on when we eat - because of the time difference - the times we train and obviously the conditions that we train in as well."
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