The Socceroos have given their hopes of qualifying for the World Cup last 16 a tremendous boost with a tense, battling 1-0 victory over Tunisia.
Mitch Duke's superb first-half header was the only goal of a hard-fought game, despite Tunisia laying siege to Australia's goal late in the second term.
However, the excellent Harry Souttar made a number of telling tackles and Mat Ryan some solid saves to preserve a rare clean sheet, Australia's first at a men's World Cup since 1974.
The Socceroos made just one change, with Nathaniel Atkinson, who was given such a torrid time by Kylian Mbappé in the opening game, missing out with an ankle injury.
Atkinson was replaced in the line-up by Fran Karačić.
Graham Arnold had warned that Tunisia would prove to be physical opposition and that proved to be the case, with the midfield skirmishes particularly intense from the off.
The Socceroos met that aggression head on, matching that physicality and unsettling the Tunisian players, who turned the ball over with alarming regularity in the opening exchanges.
That intensity created a scrappy and awkward opening 20 minutes, during which the Socceroos steadily gained the upper hand, playing most of the game in Tunisia's half.
It took time for Australia to create any real openings though, Tunisia's defence handling the Socceroos' crosses as Australia looked to work the channels and get Craig Goodwin into the game on the left.
It was through that route that Australia scored the opener thanks to a moment of individual brilliance from Duke.
Goodwin's cross from the right was deflected through to Duke, who adjusted his run magnificently before leaping with an arched back to flick the ball towards goal.
"Honestly [it's] the best moment of my life, up to date, in my football career," Duke said after the match.
"I'm just so happy and proud of the boys, we've made so many sacrifices to be here, it's the best feeling in the world."
Tunisia had been second best in the first half, but had two brilliant chances to equalise before the break.
Harry Souttar used all of his 198 centimetres to deny Mohamed Drager a goal with a magnificent sliding block.
Then, in stoppage time, skipper Youssef Msakni fired agonisingly wide from close range.
Australia had not led at half-time in 18 previous World Cup matches.
Tunisia was far better after the break, forcing Australia deeper and deeper as the game went on.
It was the Socceroos who had the best opportunity of the half though, when Jamie Maclaren's low cross skidded just in front of a sliding Matthew Leckie.
Seconds later Tunisia were up the other end, threatening to make the Socceroos pay for that profligacy, as Msakni forced Ryan into two solid saves.
The Socceroos had to hang tight in the dying minutes with Tunisia virtually camped out in Ryan's penalty area, commanding a huge number of touches, incredibly without managing to get a clear cut shot away.
The victory puts Australia firmly in the frame to progress from Group D despite their heavy first-up defeat, with Euro 2020 semifinalists Denmark waiting on Thursday AEDT.
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Let's wrap it up
Alright, that'll do us for now.
Incredible night, incredible performance from the Socceroos - one of those matches you'll be watching highlights of in the build up to the 2042 World Cup.
Don't forget, Denmark and France are playing at 3am AEDT and the result of that one will reveal exactly what the Socceroos will need to do in their final group game against the Danes.
Keep an eye out for our player ratings and Samantha Lewis's analysis from Qatar.
And our live blog will be back tomorrow morning.
See you soon.
I think Souttar is my man of the match
Very hard to choose, with so many great performances.
Scenes!
Arnold over the moon
Graham Arnold says he couldn't be prouder of the boys.
"Yes, we've achieve one win, it's nothing, there's more to do."
Update
The run to the World Cup Final starts now!
- stumcin
Update
Happy day :) :) Well done! Very proud
- Aussie Aussie Aussie!
Update
Great play. We are proud to be Australians
- Magaly
The best moment of Mitch Duke's life
Mitch Duke is emotional:
"No words, I'm going to start crying because it's such a big moment.
"Trying not to get too caught up in it because the job is not yet done.
"The best moment of my life.
"I'll go to war with these lads.
"We've got one more job to go, and try to make history for Australia."
FULL TIME: AUSTRALIA WINS 1-0!
What a battle, what an epic win!
A first World Cup win in 12 years, a first clean sheet since 1974.
Heroic performances all round, and Australia has three points!
'Land Down Under' plays over the loudspeakers, bringing back memories of Uruguay in 1997.
It's Australia's third win in 18 World Cup games.
Tunisia threw absolutely everything at Australia in that second half, and the Socceroos rose to every challenge. I am struggling to choose a man of the match: Duke, Goodwin, Leckie, Souttar, Behich, Ryan? JUST GIVE IT TO THE WHOLE TEAM.
The winning goal came in the 23rd minute via the head of Mitch Duke, but the lovely build up was typical of the fluid football that Australia played for much of the match.
Ryan flies high again!
90+5' Tunisia 0 - 1 Australia
Mat Ryan has been perfect today, and yet again he makes the right choice to come out and claim a dangerous cross.
Not long to go now for Australia.
Mooy relieves some pressure
90+3' Tunisia 0 - 1 Australia
Mooy produces a deft turn on the right flank to finally create some space and find the through pass. Tunisia are forced into a hand ball to stop the counter and that's give the Australians a moment to breathe.
Six minutes to go!
6 minutes of additional time.
There's so much space in the Tunisian half but the Socceroos can't seem to land their passes.
Make or break now.
Souttar you absolute hero! Tackle of the century!
86' Tunisia 0 - 1 Australia
Rowles has an awkward moment and spills the ball in a dangerous spot, and Khenissi raced away towards goal. Souttar came across from right back at high speed and slid in for the heroic save.
Tunisia are throwing everything forward now - this is what the World Cup is all about! Intense pressure, can Australia hang on?
Mabil and Baccus about to come on
85' Tunisia 0 - 1 Australia
As ZZ Top said - LEGS.
Bring on those fresh legs to last us these last 10 minutes or so.
Goodwin and Leckie go off.
Update
Miracles can happen! We can win the Cup!
- Cecily
Nice little period for Australia
81' Tunisia 0 - 1 Australia
They've taken a bit of the fire out of Tunisia just by hanging on for the ball a bit longer, slowing things down. It's getting desperate for the Eagles now, so something could give, at one end or the other.
Lovely build up play from Australia
77' Tunisia 0 - 1 Australia
A nice passing sequence for Australia, Hrustic getting involved at last and creating space for his teammates.
It ends with Leckie stretching for a ball and possibly pulling his calf muscle a little.
He has been immense. Is he coming off now though?
Not for now, he's back on.
Degenek comes on for Karacic
Fresh legs are important here, there are some exhausted players out there.
Mooy on the half volley!
75' Tunisia 0 - 1 Australia
With the ball bouncing around the Tunisian penalty box, Mooy has a shot from 25 metres - it fizzes over the bar.
It feels like there are more goals in this one.
Leckie so close!!
73' Tunisia 0 - 1 Australia
Behich snatches the ball down the left and feeds Maclaren in space. He snaps a cross in and Leckie shows his pace and desperately lunges at the low ball, but can't quite make contact. If he had, it would have been a goal. He was half a footstep away.
Meanwhile, Ryan is forced into a couple of great saves down the other end.