If Australia goes on to win this World Cup it should not be remembered as a procession or some kind of inevitable triumph that was so easy it may as well have been pre-ordained.
The Kangaroos had run up a score against every team they played in this tournament, but their 16-14 win over New Zealand at Elland Road in Leeds wasn't so much a game they won as a battle they survived.
New Zealand had not impressed before this night. They were perfunctory in the group stages and downright sluggish and lucky to win against Fiji last week.
But that's the thing about an ambush. You really have to sell it. Your prey can't see it coming, so when you descend upon them, knives out and beaks bloodied, they really don't know what to do about it.
And for a good while, Australia didn't know what to do about it after New Zealand came out and, in a rugby league sense, punched them directly in the face to send the green and golds to a place they haven't been all through this World Cup as they scored first and looked good doing it.
It took a try from heaven for the Kangaroos to stay alive – Ben Hunt's kick for Josh Addo-Carr's try wasn't so much a planned move as an answered prayer.
Their second score wasn't dissimilar. Jack Wighton is the kind of player who doesn't mind taking a chance on his instincts and that's all that could have told him if he was held or not when he flicked a pass out to Valentine Holmes for Australia's second.
It was their brilliance, not their systems, that kept Australia in it after the torrid first half. By contrast, New Zealand constructed their play on powerful runs from their brutish forward pack, judicious offloads and sharp choices from Dylan Brown and Jahrome Hughes.
Those are solid, stable things you can build a team around, proper foundations for any win at any level of the game. Brilliance is nice, but it's fleeting and wild, like light on rough waters. It's a hard thing to rely on, because one day you turn around looking for it and it isn't there.
New Zealand knows this better than most, because when they beat Australia it's almost always on the back of that kind of magic. Either Benji Marshall or Stacey Jones or Shaun Johnson or somebody else like that reaches up and grabs the sun and skins the Kangaroos.
But not this time. This wasn't a game that was pulled out of the fire, it was a contest that was hammered into reality. This time it was the Kangaroos who were hoping one of their guys could pull something out and break the system, and it was Australia left clutching for answers as New Zealand hammered away time and again.
The Kiwis were the ones who looked like the team who'd put everyone they'd faced to the sword and it was New Zealand roaring in Kangaroo faces after forcing errors and daring Australia to do something about it.
But here's the thing about taking down a juggernaut – you can't be switching off, not even for a second. The Australians are so accustomed to dominating and so adept at seizing control of a match like it's a birthright that if they're given even the slightest chance, they'll take the ascendancy and never let go.
New Zealand, for all their fire and fury, gave Australia just enough. It was only an error here, or a lazy defensive effort there – against any other side, it wouldn't have mattered, but against Australia that's the way it goes.
Cameron Murray's try, which gave Australia a lead midway through the second half they never surrendered, wasn't anything special.
Of all the ways for New Zealand to concede the winner, this was the cruellest. It wasn't Latrell Mitchell sending his opposite number to the land of wind and ghosts with a huge fend, nor was it Addo-Carr finding some space and running so fast he left the grass aflame in his wake.
It was just Murray hitting it up off a tap restart from 10 metres out, the kind of thing you see in the under-10s when one of the bigger, stronger kids picks out somebody he outweighs by 20kg and decides he's going to make this the worst day of their life.
You don't have to be perfect to beat Australia, but you have to be close. You can't give them easy chances and you have to nail your own. If you're a second too early or too late, you'll miss it. If you're half a step too slow or too fast, you won't catch it.
New Zealand had one late chance in the final minutes, after Jordan Rapana conjured a break from nowhere to put them on the attack.
They went right with numbers and things were looking nice. Hughes had the ball in his hands with a try on his mind and, on tackle one, he put a kick in for Peta Hiku. It's easy to say it was a poor option because it didn't work, but New Zealand had reached the brink of victory by trusting Hughes to make those choices.
Addo-Carr shadowed the ball over the touch in-goal line, Hiku dived and put it down just a moment too late, the Kiwis never got a chance and Australia were bound for Old Trafford.
They await either England or Samoa and will be warm favourites against either. If there was any complacency in them, or any chance of them being caught underdone, it has now been erased.
New Zealand pushed Australia to the brink, but the Kangaroos know how to live beyond that point.
They found the things they needed when it mattered. That's not an easy thing to do. Not everybody knows how.
But then again, if everyone knew how to do it then winning a World Cup wouldn't be so hard at all.
