Keisuke Honda's penalty sank Iraq in a 1-0 victory as Japan moved to the brink of qualification from Asian Cup Group D on Friday.
Japan took firm control of Asian Cup Group D as Keisuke Honda's penalty ensured a 1-0 victory over Iraq in Brisbane on Friday.
Both teams headed into the encounter at Suncorp Stadium having won their pool openers and seeking to put one foot in the knockout stages.
And it was defending champions Japan who clinched the points, Javier Aguirre's side proving too strong for Iraq and their only disappointment will be the fact they failed to win by a more comfortable scoreline.
Japan took the lead in the first half when Honda scored a penalty for the second group match in a row after also netting from 12 yards in the 4-0 beating of Palestine.
The Milan midfielder impressed throughout and hit the woodwork on three occasions, the last of which coming when he somehow managed to hit the post with the goal unguarded.
It made no difference, though, and Japan now just need to avoid defeat against Jordan to guarantee their qualification from the knockout stages.
Iraq - who beat Jordan 1-0 in their opener - must better the result of Ray Wilkins' men in their contest with Palestine.
Japan started on the front foot and Shinji Kagawa fired just wide after good set-up play from Honda, who troubled the woodwork for the first time soon after from Yuto Nagatomo's pin-point delivery inside the six-yard area.
Iraq goalkeeper Jalal Hassan then made a superb point-blank save from Kagawa's close-range shot, but from the rebound Honda was sandwiched by two challenges and referee Alireza Faghani pointed to the spot.
Honda picked himself and confidently rolled the penalty into the bottom right-hand corner to hand Japan a 23rd-minute lead.
Shinji Okazaki could have doubled the lead but he headed straight at Hassan when unmarked in the area, while at the other end Younis Mahmoud failed to make clean contact with Amjad Kalaf's low centre.
The impressive Honda went agonisingly close to a second shortly after the break when he bent a superb 25-yard effort onto the crossbar.
From there Iraq started to display signs of improvement and Radhi Shenaishil's men showed threats on both flanks, although Japan's defence soundly dealt with the pressure.
Having soaked up Iraq's advances, Japan should have ended the contest in the 65th minute when Nagatomo's low centre across the six-yard box picked out Honda, who inexplicably hit the post with the goal wide open.
Japan continued to turn the screw as Iraq appeared to tire and Kagawa tested Hassan with a stinging shot from the edge of the box.
Aguirre's men had to settle for the one goal, though, but Japan can head into the final group stage fixture safe in the knowledge that their fate lies firmly in their own hands.