Australia's Garang Kuol says he lived a dream when becoming the youngest footballer since Pele to feature in a World Cup knockout game.

Kuol, aged 18 and 79 days, crossed paths with Argentina legend Lionel Messi during the Socceroos' 2-1 loss in Doha.

"Going one-on-one with Messi for a bit - unreal, I could say a dream," he told reporters.

Kuol is the youngest to play a knockout fixture at the tournament since a 17-year-old Pele in 1958.

And he adds Messi to a list including France star Kylian Mbappe that he has tangled with during his debut World Cup.

"Just their level of confidence and ability," he said.

"I try and mirror their game."

Kuol, who in January will transfer from Central Coast Mariners in the A-League Men to Newcastle in the English Premier League, believes it will not be long before the Socceroos challenge football's world superpowers.

"The sport in Australia keeps growing and keeps producing better and better players as time goes by," he said.

"In the future you will see a team that is at the same level as Argentina, Brazil and all those teams."