Two sublime goals by Australia's Nestory Irankunda and Connor Metcalfe sealed a 2-0 win in Vancouver on Saturday as Turkey suffered defeat on their first return to the men's World Cup since finishing third in 2002.
Paul Okon-Engstler's perfect long pass over the top allowed Watford's Irankunda to run onto the ball, but the 20-year-old still had much to do and finished in style.
"Unreal, it is a dream come true. We have got the win now," said Irankunda, the youngest men's World Cup scorer for Australia and not a definite starter before kick-off.
"It feels amazing, you have got to thank the staff, thank the nation, they have got the belief in me."
The 27th-minute goal stung the Turks into action and they later dominated the second half without carving out many clear-cut chances.
They paid for their profligacy as Australia broke on 75 minutes and St Pauli's Metcalfe was given too much space to advance, finding the near corner from just outside the box.
Midfielder Metcalfe failed to scored in the Bundesliga last term when the Hamburg side were relegated.
Australia sprang a surprise, with young goalkeeper Patrick Beach preferred to veteran Mathew Ryan, but he shone on his World Cup debut with several saves, including a late stop from captain Hakan Çalhanoğlu. The plan to absorb pressure and counter worked out perfectly.
The Socceroos, in their sixth straight men's World Cup, used their experience elsewhere to see out the Group D win and sit just below co-hosts and next opponents the US, who beat Paraguay 4-1 in their opener.
Australia reached the last 16 for the second time four years' ago in Qatar and are now well-placed to make the knock-outs in this expanded edition in North America.
"I'm proud. Happy for a wonderful young group of men," said Australia coach Tony Popović. "Proud of the staff and the work they put in."
On the decisions to field Beach, Irankunda and Okon-Engstler, he added: "I have got a lot of belief in the young man (Beach). It was quite special, you see the young boys combining for the (first) goal."
Turkey meanwhile have thinking to do and coach Vincenzo Montella, a rare Italian at these finals, must find a way to beat Paraguay on Friday to offer hope of progression after five missed tournaments.
Forward Kerem Aktürkoğlu said: "We knew they would sit back and look for counter-attacks. As a team, we couldn’t stop those counter-attacks. We missed a chance, then conceded the first goal before we knew it.
"It’s demoralising to fall behind whilst playing well and having possession. Our finishing needed to be better."
