Australia's chances of progressing to the next stage of the Under-20 World Cup were dealt a massive blow when they lost 2-1 to El Salvador on Tuesday.
The Young Socceroos will now need to beat host nation Turkey on Saturday (AEST) in their final Pool C clash to stand any chance of progression to the last 16.
Playing in the north-east town of Rize, Australia didn't take long to get on the scoreboard through a stunning Josh Brillante strike in the ninth minute.
But the Central Americans struck back twice in the first half to take control of the match and then defended astutely to record the upset victory.
With the El Salvador defence backing off, Brillante drove the ball low inside the left-hand post from 25 metres, leaving goalkeeper Rolando Morales with little chance.
Diego Coca equalised for El Salvador eight minutes later as the Australian defence stood still.
Kevin Barahona headed Jairo Henriquez's cross along the goalmouth and the El Salvador No.10 took advantage to nod home.
Adam Taggart had an opportunity soon after for the Young Socceroos but it was El Salvador who got in front in the 40th minute.
Winning the ball in Australia's half, Miguel Ochoa broke quickly and played square to a lunging Jose Pena, who beat goalkeeper Paul Izzo first-time to hand his side a deserved lead.
Jamie McLaren replaced 16-year-old Perth Glory midfielder Daniel De Silva midway through the second half and had a late chance with time winding down after an El Salvador back pass.
But Paul Okon's side couldn't find a way through and now sit last in their group on one point after drawing 1-1 with Colombia last Saturday.
"Unfortunately we kept the lead for only eight minutes, with a cheap goal. Then it becomes a bit of a battle, when they get on even terms," Australian coach Okon said.
"The effort and application was there, and we just lacked that ability to find something in the final third. That's what you need when you're chasing the game."
"If we beat Turkey, we get to four points and there's still an opportunity to qualify."