Australia coach Guus Hiddink paid tribute to the fitness and work rate of his team after their stunning comeback to beat Japan 3-1 in their World Cup Group F opener.

The Socceroos netted three times in the last six -minutes - twice through Everton's Tim Cahill and once through former Portsmouth forward John Aloisi - after Celtic's Shunsuke Nakamura had given Japan the lead.

"The last announcement I have to make them (is to work hard), because they never stop working," Dutch coach Hiddink said.

"This was part of the strategy we planned that if near the end of the game the score was neutral or we were down, that we didn't want to panic.

"We had to build up the game with the strikers we had and there was Timmy with the (equalising) goal from the Lucas Neill throw-in, which we practised."

Hiddink also told his players to savour creating history but not to get too carried away by the win, with two group games still to come.

"Let's enjoy this moment, we are here now in Germany, so enjoy it but keep working hard," he added.

Japan coach Zico admitted the introduction in the second half of tall strikers Joshua Kennedy and Aloisi had put his side under defensive pressure.

"It's a difficult situation when you are playing against three strikers (Kennedy, Aloisi and Mark Viduka) all above six feet," he said.

"It doesn't matter how much training and playing you do against that type of attack, it's difficult to play against.

"But Japan has to score when we have opportunities and when we are on the counter-attack because a lot of teams like to kick long balls into the Japan area."

Zico also admitted it would be tough for his team to qualify for the second round now, adding he was hoping that Croatia would not get a draw with world champions Brazil in the other opening Group F clash tomorrow.

"The Croatia game becomes critical for us now," he said.

"We have to win that and then worry about our goal difference."