Kewell, 29, whose goal against Croatia lifted Australia into the Round of 16 of the 2006 FIFA World Cup™ finals, grabbed the winner two minutes into the second half after the home side had ridden their luck in the opening spell.
"I think we rode our luck. Iraq created quite a few chances today and a couple of balls went their way but again we had a great 'keeper (Mark Schwarzer) who stopped them," said Kewell.
Skipper Kewell eased Australia's anxieties with a well-taken header, outjumping his marker Abdul Amir Haidar to nod home Brett Emerton's cross from the right. It was the tenth goal in 32 international appearances for Kewell, who is emerging from a couple of injury-blighted seasons. Kewell was taken off with 13 minutes left to rapturous applause from the home crowd.
Iraq came close to grabbing a draw in the final ten minutes, with Ali Hussein Rehema and Mulla Mohammed Hawar denied by last-ditch saves from Schwarzer.
"Today was not what we deserved. ," Australia coach Pim Verbeek said.
Asian champions Iraq did not even know they would be playing the Australians until FIFA reversed a decision on Thursday to suspend them from competition over political interference from their government.
"Of course, it affected our players a lot, but we always play under pressure and we are the only football team in the world that plays outside of its country," Iraq coach Adnan Hamad said.
"My team tried to win so we could get a second chance in the FIFA World Cup qualifiers, but there's still a chance for the Iraqi team and I have faith in my team," Hamad said.
"It's going to be great next week. It's going to be difficult with the heat, but we are well prepared, we know what we're going to deal with because we've been in Asia so we are going to be well equipped," Kewell said.
Emad Mohammed rattled the bar in the fifth minute after goalkeeper Mark Schwarzer had punched clear a corner. Emad later found himself unmarked in the box after sloppy Australian marking but his shot was deflected for a corner by Schwarzer's leg in the 26th minute and skipper Younis Mahmoud had a free header in the six-yard box, the chance going wide of Schwarzer's right post.
Kewell came in for special attention from the Iraqi defence and he was fouled three times, two of the offences leading to yellow cards for defenders Rehema and Haidar.
The Iraqis, like they did in their 3-1 win at last year's AFC Asian Cup, frustrated the Australians with their stoppages during play and several times Socceroo players lost their cool, remonstrating with Uzbekistan referee Ravshan Irmatov.