If a fearsome, lightning-fast attack has the Matildas billed as Women's World Cup contenders, it's their newly-miserly defence that could make it a reality.
In just over two years, Tony Gustavsson's back line has transformed from the leakiest of sieves to a near watertight shield.
Recent clean sheets in victories against world No.5 France, world No.4 England and world No.3 Sweden are a world away from the 5-2 loss to Germany and 5-0 thrashing from the Netherlands that marked Gustavsson's first two games.
There is newfound defensive depth, partly inspired by exceptional inclusion Clare Hunt, and the rises of Charlotte Grant and Courtney Nevin.
But there is also a fresh steeliness.
Jens Fjellstrom officially became Gustavsson's full-time assistant in April, after a short stint during last year's Asian Cup.
He has worked closely with the defence - and his message has been simple.
"I say to them that I don't think good defending is looking at a team defending when everything goes well," Fjellstrom told AAP.
"To me, good defending is looking when the s*** hits the fan -because that will happen at times.
"They are at a very good point right now where they defend as a unit and they support each other and they cover up for each other and that's probably good if you want to defend well."
That was evident in Friday's 1-0 victory over France, with Hunt, Steph Catley and goalkeeper Mackenzie Arnold all making crucial blocks in the final warm up game.
It's been a long journey.
A year ago, Fjellstrom and Gustavsson narrowed their focus, aware a strong defence would also open up the game for Australia's terrifying attack on transition.
"We said 'let's focus on building a strong defence and try to do it layer by layer' because if you come into one camp with five new pieces that you're supposed to put in that puzzle, it will crack down quite quickly," Fjellstrom said.
"But if we just start with one piece, and then next time another piece and another layer and another layer and another layer, all of a sudden, when you're having a couple of clean sheets, when you're having a lot of wins coming in a streak, you build a thick skin.
"So you can take 20 minutes of a game not playing that well but you still stay in the game.
"You can actually take a hit playing (and losing to) Scotland without doubting what you're doing and bouncing back and winning against England, who had been unbeaten in 30 games."
Building those layers included backing Grant to cover for Ellie Carpenter, then Catley.
It included throwing speedy centre-back Hunt into the fray with Clare Polkinghorne five months out from a World Cup.
It's why an injured Alanna Kennedy was consistently brought into camp to keep up to speed, and why Aivi Luik extended her international career as a centre-back.
On Friday night, Kennedy combined with Hunt for the first time with aplomb, marking a fourth clean sheet, and fifth win, from Hunt's six games.
"A long, long time ago we started talking about the basics and making sure the details of our back line are right, that we're ticking all the boxes," Catley told AAP.
"We've been progressing to a point where we say we're ready for like a World Cup final."
