A costly mistake from Socceroos defender Milos Degenek in the second-half saw his stray back pass hand Ali Mabkhout the only goal of the game.
The green and gold pushed hard for an equaliser but were held goalless for a third game at the tournament with Jackson Irvine struggling to hide his emotions at the full-time whistle.
Though clearly devastated, Irvine stood by Degenek as Australia looks to pick up the pieces of an earlier than expected Asian Cup exit
"Obviously it's extraordinarily tough to take and hard to wrap your emotions around it so quickly after the game," Irvine told Fox Sports.
"We could have created more, made more use of the ball when we had it, but it was down to one moment.
"We win as a team, we lose as a team. There will be tough moments for every player and we have to deal with the criticism that will come and that's part of it.
"I told Degenek to get on his feet and keep his head up. He's been one of our most promising players, he's got a huge career ahead of him and while I haven't seen the incident, I think he's too honest for his own good."