Coach Graham Arnold said "the old Aussie way" helped his side beat Tunisia 1-0 on November 26 to keep their World Cup alive but warned his players they had achieved nothing yet.

A Mitch Duke header in the first half combined with some dogged defending in the second revived the Socceroos' hopes of reaching the last 16 for only a second time.

They face Denmark in their last group game in Qatar with their fate in their own hands.

"Our fight, our grit, our determination – the old Aussie way was very important tonight and very, very proud of the boys," said Arnold, whose side were thumped 4-1 by holders France in their opener.

The Group D clash with Tunisia was beamed on primetime television back home and Arnold said he expects there will be "a few hangovers in the morning".

"The fans back at home – it's a moment they'll remember for the rest of their lives," said Arnold, 59.

"I said to the boys before the game: let's put a smile on the nation's face."

The fans may be feeling it in the morning, but Arnold has ordered his players to stay focused.

"That one game is done. I don't want any emotion from the players, I don't want them up all night looking at social media and all that stuff," he said.

"I've just said to them, no doubt that the nation is extremely proud.

"But we've done nothing. We've achieved something we can talk about after the tournament but we are here to go as far as we can go.

"I don't want any celebrations. Just enjoy this couple of minutes with the fans and then get yourself in the dressing room, recover and get ready for the next one."