A stunning solo goal from Mathew Leckie has sunk Denmark 1-0 and sent Australia into the World Cup knockout stage for just the second time, where they will face Lionel Messi's Argentina.
Leckie's superb left-footed strike ensured the Socceroos followed the feats of the so-called golden generation in 2006 in reaching the round of 16.
The stalwart, played into space by Riley McGree, broke an hour-long deadlock with a slicing run at his marker Joakim Maehle after gathering some 30m from goal.
First to his right, then onto his left, Leckie twisted and turned his opponent and fired a low left-footer to instantly enter Australian football folklore.
"As the ball was rolling in, I saw it going in, I was so excited and so happy," Leckie said after the match.
"By the celebration you see how much emotion there was.
"I'm just so proud. We've worked so hard. This is my third World Cup now and I've had my chances in previous World Cups to score, wasn't meant to be.
"My first World Cup (goal) is probably one of the most important goals for me and for the team."
Leckie's timing was perfect in more ways than one.
In the other simultaneous game in Australia's group, outsiders Tunisia had scored just three minutes earlier against holders France, who rested almost their entire first-choice side.
The Tunisian goal momentarily lifted them to second in the group behind the French only for Leckie to restore the Socceroos into that prized slot.
Australia's date with Argentina was confirmed hours after the Socceroos' win when Messi's men beat Poland 2-0 to secure top spot in Group D.
That game will be played at 6am Sunday AEDT.
"We always knew we could do it. We believed as a group," Leckie said.
"We had our doubters. With our spirit, our belief, our work ethic and how close we are, it shows on the pitch. That last 15, 20 minutes we battled to the end."
Leckie and his captain Mat Ryan, barring injury, will break the Australian record for most cup games in the knockout encounter.
Against the Danes, the duo both made their ninth cup appearance, equalling Tim Cahill and Marco Bresciano's record.
Goalkeeper Ryan was called into action early as the Socceroos lacked spark and were forced to repel a series of attacks from the Danes, ranked 10th in the world, 28 slots higher than Australia.
Ryan made a reflex save in the 11th minute from a thundering Mathias Jensen shot, the Australian parrying away with both hands above his head.
The Danes controlled two-thirds of possession, having almost double the passes of Australia in the opening half yet the Socceroos crafted some half-chances mainly courtesy of midfielder Riley McGree.
The attacking midfielder had the first shot of the match — a long-range left footer in the third minute which was blocked in the box — and another some 20 minutes later after Leckie and Mitch Duke headers played him into space.
After a scoreless half, Socceroos coach Graham Arnold replaced Craig Goodwin, who lacked his customary fizz on the flank, with Keanu Baccus.
And Arnold must have revved up his players, who produced a much improved second half to create another landmark.
"A lot of belief, a lot of hard work," coach Graham Arnold said.
"These boys came in with a great mind set. We've been working on this for four years about the belief and the energy and the focus. You know, I can see in their eyes they were ready tonight."
Asked how the team would celebrate, Arnold was firm in his response.
"No celebrations," he said.
"As I said to the boys, that's why we won after a great win against Tunisia. No celebrations, no emotion. Sleep. No social media."
Re-live all the action and reaction in our live blog below.
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Key events
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Live updates
Final scores
That's where we'll park the live coverage for now
But there is so much more to come from ABC Sport this morning and over the next few days as we build up to Australia's round of 16 clash on Sunday morning.
Who will they play? We'll find out in a few short hours - all of Argentina, Poland and Saudi Arabia are possibilities.
We'll have plenty of analysis, reaction and wash up from this famous morning for Australian sport through the day, so don't go far.
Up the Socceroos.
The Aussies in Doha are loving it
A brief break in the social media ban
I'm Graham Arnold will allow the guys a quick little post or two.
Drink it in
Don't mind me, just going to sit here staring at this all day (until I fall asleep on my keyboard which is a very real possibility).
I remember the morning of the Croatia game in '06 so vividly, the amazement of what had been achieved and the sudden realisation that anything was possible, on the greatest stage of all. This feels the same. Football hurts a lot of the time, but moments like this make it all worthwhile.
It has been decreed
'Like blocking bullets': Degenek leaves it all on the pitch
Thrown into the starting XI for this game, Degenek responded after some early concerns to play a pivotal role in a titanic defensive performance.
"I think the tank's empty. But we have a couple of days to turn around. Then we go again. The tank gets empty again and recover until we win the thing. Hopefully.
"Look, I just did my job to the best of my abilities. I thought I helped with my dedication and desire to win and sometimes that's enough to get us over the line. Which it was today.
"You just have to be concentrated and just be aware where they are. I guess every ball is like the last ball, you defend for your life. It's like trying to block bullets that are going to hit your family. That's what we're doing. We're blocking, throwing bodies at it. That's what we've done."
Fed Square going bananas
It's Mat Leckie's night
Looks like he was FIFA's player of the match, which is certainly hard to argue. He's given Richarlison a run for his money with that goal tonight, there won't be many better scored in Qatar this tournament.
Update
What an extraordinary achievement. 👏
- david
Update
It’s not a shock. It’s destiny!!!
- Phil K
Update
Aaahhhhhhhh what a match!!! Longest 36 minutes of my life. How are we all going to sleep after that?!
- M
'No celebrations', says Arnie
Whatever you say, boss. Lets win this whole damn thing.
"No celebrations. As I said to the boys, that's why we won after a great win against Tunisia.
"No celebrations, no emotion. Sleep. No social media.
"These boys come in with a great mind set. We've been working on this for four years about the belief and the energy and the focus.
"You know, I can see in their eyes they were ready tonight."
A famous day for Australian football
What could this do for the game in this country? On the eve of Australia hosting the Women's World Cup, just how much of an impact could this generation of Socceroos make on the wider public? The 2006 crop changed the game here, and it feels like we are on the precipice of something even bigger right now.
Graham Arnold mate
A lot of words being eaten in Australia this morning. Graham Arnold has proved so many people wrong, and has created a legacy for himself that can now no longer be questioned.
The absolute funnest of facts
Fun fact: In a group featuring Champion France, Dark-Horse Denmark and Tunisia, Australia scored first against them all.
- Jason
France ended up losing 1-0 to Tunisia too after having a late goal chalked off by VAR, so the Socceroos finished second in Group D only on goal difference. Staggering.
Our Socceroos heroes
THAT'S IT! SOCCEROOS WIN! They are into the last 16!
I'm speechless. They did it. And they didn't have to rely on anyone else, they didn't have to scrape through. They went out there and SEIZED it. Graham Arnold's Socceroos have done something NO Australian team has ever done in a World Cup - they have won two games in the group stage.
This group of underdogs have come together and achieved something truly special. It's unbelievable. I can't believe it.
One minute to go
95': Australia 1-0 Denmark -- Tunisia 1-0 France
Another Denmark corner. Cornelius had a free header at the back post. It lands on the roof of the net.
Sakes. Come on.
Two minutes to go
94': Australia 1-0 Denmark -- Tunisia 1-0 France
Denmark have a corner and Schmeichel is sent up for it. The ball sails straight into Mat Ryan's glorious gloves. Nearly there.