Asian champions Japan shrugged off the late injury withdrawal of Manchester United's Shinji Kagawa to beat Iraq 1-0 and stay top of their group in their 2014 World Cup qualifier on Tuesday.
Japan, hit by the loss of Kagawa just before kick-off with back pain, rode their luck at times in front of a packed Saitama Stadium but ended with all three points thanks to Ryoichi Maeda's headed goal after 25 minutes.
The result gives Japan, who have 10 points from four games, an eight-point lead at the top of Group B ahead of Tuesday's later matches. The top two in two groups of five earn an automatic ticket to Brazil.
The game provided an unhappy return for former Japan coach Zico, whose makeshift Iraq line-up -- hit by a series of injuries and suspensions -- tested the hosts, especially in the opening exchanges.
Iraq, who were unbeaten after drawing their first two games, started brightly and Japanese keeper Eiji Kawashima was forced into action with a key stop in the opening minutes.
But it was Japan who got the breakthrough when Stuttgart's Shinji Okazaki fed Jubilo Iwata striker Maeda in the six-yard box for the game's only goal.
As half-time neared, the dangerous Ahmed Yaseen tested Kawashima with a goal-bound shot that was curling inside the far post.
Japan looked more comfortable after the break, with CSKA Moscow playmaker Keisuke Honda a particular threat, and they finished the match with high hopes of reaching their fifth straight World Cup in Brazil.
"It was really tough," said Japan's coach Alberto Zaccheroni. "We want to win the ticket to the World Cup as quickly as possible. I'm going to start thinking about our next game," added the Italian.
Japan will next play Oman away on November 14, while Iraq host Australia -- in a third-party venue, due to security fears -- on October 16.
"We tried hard to win this game, but it ended in a defeat. Japan prepared for the game very well," Zico said.
Kagawa told reporters he felt a twinge in his lower back during training, but added that the injury did not seem "that serious".
"I felt a twinge in the back during practice when I was on the ball. I had some treatment but didn't want to risk causing the team trouble by playing," Kagawa said, according to Kyodo news agency.
"Obviously it's a shame I wasn't able to play... It's not that serious and I don't think it will keep me out for long."
His comments will come as a relief to Manchester United boss Alex Ferguson, whose team have a packed schedule with Wigan Athletic at home on Saturday and Galatasaray in the Champions League next week.