The Liverpool midfielder stepped up to take Australia's first spot-kick in the shootout after the match at the My Dinh National Stadium in Hanoi ended 1-1, but was denied by Japan goalkeeper Yoshikatsu Kawaguchi.

And after team-mate Lucas Neill was also denied, the Socceroos and goalkeeper Mark Schwarzer were unable to recover as Ivica Osim's side remained on course for a third consecutive continental title this July after claiming a 4-3 shootout victory.

Australia were making their first appearance in the Asian Cup after switching to the Asian Football Confederation (AFC), but struggled to a draw with Oman and crashed to a defeat against Iraq in Group A before re-grouping to down Thailand and secure a place in the last eight.

"I think we will now take a different approach to Asia now. We have had a taste of it and we know what it's all about and we must have a different attitude," said Kewell.

"The main lesson we will learn is the next time we try to qualify for the World Cup it's not going to be easy as we think and we will make sure we play 10 times better than we did in this Asian Cup.

"I think this whole competition has been an upside down tournament for us. We have come out and played bad at the start and then picked ourselves up. You can look at a lot of things, but we had our chances and we should have put them away.

"It was a culture shock and I thought we did enough. Japan had a lot of possession, but I don't think they caused us that many problems."

Kewell also jumped to the defence of team-mate Vincenzo Grella, who was dismissed with 14 minutes remaining after appearing to catch Japan goalscorer Naohiro Takahara in the face with his arm as the pair rose to challenge for a ball.

John Aloisi had handed the Socceroos a 69th-minute lead as he converted Kewell's inswinging corner before Takahara capitalised on an error from Sydney FC defender Mark Milligan to fire past Schwarzer three minutes later.

"As far as I'm aware it was a good challenge," added Kewell. "Vinnie always goes for the ball, always wins it and puts his heart and soul into it so I don't think he would have done anything deliberately."