DOHA, Qatar - Lionel Messi produced a moment of trademark quality to score the opener in a 2-1 win over Australia and help send Argentina into the quarter-finals of the World Cup on Saturday.
Messi's 789th goal in his 1,000th career appearance -- but first in the knockout rounds of the World Cup -- helped set up a last-eight clash with the unbeaten Netherlands on Friday.
Julian Alvarez scored the other in the 57th minute after some calamitous Australian defending, before Enzo Fernandez's 77th-minute deflected own goal set up an unexpectedly nervy finale.
Argentina's players celebrated wildly in front of their massed ranks of fans and man-of-the-match Messi paid tribute to them for dragging the team across the line.
"Amazing feelings and I am really happy to share these beautiful and happy moments with them all," said the 35-year-old, who is trying to win the World Cup for the first time in what will surely be his last attempt.
"I know the effort they are making to be here with us and I know how much they enjoyed it.
"There is a bond we have -- it is something beautiful, it is what the national team should be."
Messi's classy first-half goal, bending the ball into the bottom corner, broke the resistance and ultimately the hearts of a gutsy Australian side who defied all expectations in Qatar and went down fighting.
- Messi strikes -
Australia's yellow-shirted fans were vastly outnumbered among the packed crowd at the 45,000-capacity Ahmad bin Ali Stadium and were drowned out by Argentina's boisterous and bouncing supporters.
The Socceroos were huge underdogs but this has been a World Cup of shocks.
Two-time champions Argentina were the victim of arguably the biggest in Qatar when they went down 2-1 to Saudi Arabia in their opening match.
Argentina had Australia pinned back but coach Graham Arnold's men were resolute and growing in confidence as an uninspiring first half wore on.
Argentina badly needed something special and in Messi they got it 10 minutes from the break.
Alexis Mac Allister fed defender Nicolas Otamendi, who was still in the box for an Argentina free-kick, and he miscontrolled it into the path of Messi who bent the ball left-footed along the ground into the corner.
Australia had only got this far once before, in 2006, and they needed to attack in the second half.
Instead, they self-destructed. Goalkeeper and captain Mathew Ryan tried to play out under fierce pressure in his box from hard-running Rodrigo De Paul just before the hour and was dispossessed by Alvarez.
The Manchester City striker, 22, nipped in, stole the ball from Ryan and swivelled to slot into an empty net for his second goal in as many games.
The Socceroos looked dead and buried but substitute Craig Goodwin latched onto a loose clearance and his shot hit Fernandez and ricocheted in with 13 minutes left.
Aziz Behich then went on a superb mazy run from left-back, beating three Argentina players before Lisandro Martinez made a vital last-ditch challenge.
Both sides had chances in the last 10 minutes, the last falling to Australian teenager Garang Kuol deep in injury time, but goalkeeper Emiliano Martinez made a desperate save.
- Arnold proud -
Arnold, who assembled a team full of hard work and defensive clout, said he was immensely proud of their surprise run to the last 16.
"I just told the boys I could not be more proud of the effort and they gave everything to me and the nation," said Arnold, whose contract is up and will now take time to think through his future.
"Of course we are disappointed because we felt we could have got a bit more out of the game.
"It's all about making the nation proud and I'm pretty sure we did that.
"Everyone said we were the worst Socceroos to ever qualify for the World Cup and the worst Socceroos ever.
"That's gone now."