As Australia''s World Cup comes to an end, we look back at history made by the defence (and attack), a brutal reminder of what knockout football is about, a legacy for coach Graham Arnold, hope for the future of the Socceroos and Aussie fans joining the world party.
Here are five talking points from Australia's World Cup campaign:
Australia's whole-hearted defence gets a record
Things didn't start well for the Australian defence, when the Socceroos shipped four goals in the opening match of the tournament against France.
A loss and a big hit to goal difference could have all but ended the Socceroos' campaign, but there was more to come from the Australian back line.
Before this tournament, the only clean sheet Australia had kept in the finals was 48 years ago, when the Socceroos had a goalless draw with Chile at the 1974 World Cup.
Not too many were expecting similar results, particularly after the French game, but Australia managed to keep their opposition out not once, but twice.
Against Tunisia, the Socceroos hung on to a 1-0 lead in a frantic finish, topped by Harry Souttar's brilliant tackle that snuffed out an attack in the dying minutes to preserve the win.
Then with the tournament on the line against Denmark, Australia did it again, keeping Christian Eriksen and the Danes scoreless for 90 minutes, securing an unprecedented second straight win and a place in the knockout stages.
It was the most successful group stage in six Australian attempts, better even than the 'golden generation' of Tim Cahill, Mark Schwarzer, Mark Viduka, Harry Kewell and others — and it was largely founded on heroic defence.
Graham Arnold leaves a legacy
It's a tough job being a national team coach. You have the nation's hopes riding on you, and the critics come if you don't get the results, or play the football they want — or both.
It's fair to say that many have been frustrated with Arnold's stint as coach of the Socceroos, with the team seemingly destined to miss out on Qatar until a late run of results and a now-famous penalty shootout against Peru.
But Arnold — involved with the Socceroos as a player or coach on and off for a staggering 37 years — had an idea of what he wanted to achieve and went after it.
He instilled in his team a single-mindedness and belief, even when — perhaps especially when — others didn't really believe there was a chance.
Not all of the play from the Socceroos was pretty, but it proved pretty effective. Few would have predicted Australia to come second in the group, trailing France only on goal difference.
As the first Australian-born Socceroos coach to win a game at the World Cup, never mind to take them to the round of 16, Arnold has changed a few minds in this tournament — and he has definitely left a legacy for what he has achieved with this team.
Tough lessons for Aussies in knockout stage
The only other time Australia has made the last 16 of the World Cup they were beaten 1-0 by a 10-man Italy team, conceding an injury-time penalty to exit the tournament.
There was not heartbreak on that scale for the Socceroos this time around, but there was a reminder of what it takes to win games at the knockout stage of the tournament.
The one doing much of the reminding was a certain Argentinian number 10, Lionel Messi, who converted what was his team's first clear-cut chance in the 35th minute of play.
The second, and more damaging lesson, was learned with the game on the line in the second half.
Sometimes when you're playing knockout football, an opposition team will just play too well and get the win.
Other times, however, it's not a one-sided contest — and that's when errors need to be kept to a minimum, particularly around goal.
A split-second decision by Mat Ryan to try and evade the Argentinian attack from a problematic backpass, led to the goalie losing the ball — it trickled away and fell to Julian Alvarez, who turned and put it in the net.
It was rough on Ryan, who had done his level best to keep the Socceroos in the hunt in all their games. But that's World Cup football — your chances can disappear in a split-second.
It's to the Socceroos' credit that they kept trying, and managed a goal from an own goal by Enzo Fernandez after a deflected shot by Craig Goodwin. But it wasn't to be enough.
Socceroos fall short, but future is bright
With their tournament on the line, and immense pressure on every pass, tackle and move, the Socceroos kept trying to the very last.
In the sixth minute of added time, Australia had one last chance as the ball came over to Garang Kuol, whose shot on the turn was parried then caught by Argentinian keeper Emiliano Martinez to end Socceroo hopes.
But the moment showed what Kuol can do, and what he means for the Socceroos.
He didn't have many minutes in this tournament, missing the second and third games in the group and only coming on at 4-1 down against France.
But at 18 years 79 days, he is the youngest player since Brazilian legend Pele to play in a match in the knockout stages of the World Cup.
Having just secured a move to Premier League club Newcastle — although likely to be loaned out to another European side in the New Year — the future is bright for the young Aussie. In four year's time, he may well be at the heart of the Socceroos attack for the 2026 World Cup.
Memories made as fans fully engaged with Socceroos tilt
The FIFA World Cup offers a reminder every four years that football is indeed the world game, and that the action and results at the tournament trigger huge moments and emotions for people on all continents.
At this tournament, Australian fans joined the world party, and the world noticed.
The pictures and footage from Federation Square in Melbourne went round the world, as people went wild in a sea of limbs as Australia beat Tunisia.
The crowds grew for the Denmark game, and then live-site mania swept the country for this morning's knockout match.
From Melbourne to Sydney, Adelaide to Brisbane, venues were full of Aussie supporters riding every tackle, groaning at the Argentina goals, and going mad for the second half goal that gave the Socceroos hope.
Win, lose or draw, it is a reminder of football's potential in this country.
And if nothing else, it provides a tantalising glimpse of what things could look like next July and August, as Australia co-hosts the Women's World Cup. What will crowds look like for the Matildas?
