Asian Cup: Hussein stars as Iraq stun Japan to seal last 16 spot
Japan were unbeaten against the West Asian side in their last nine games and Iraq's victory propelled them to the top of the group standings with six points from two games while Hajime Moriyasu's side have three points.
Roared on by thousands of Iraqi supporters in the stadium, Iraq got on the board inside five minutes when Japan goalkeeper Zion Suzuki failed to deal with a cross, parrying the ball straight to Hussein who headed it into the top corner.
Iraq's strategy to unsettle Japan was to stay compact and use their physicality early on, which worked to an extent until the East Asian side began using their pace and finding space on the wings to put crosses into the box.
But Iraq doubled their lead on the stroke of halftime when Ahmed Al-Hajjaj skipped past his marker and floated in a cross that was headed home from point-blank range by Hussein as the Iraqi fans at the Education City Stadium went delirious.
Moriyasu made five substitutions after the restart and, although Japan had a penalty claim denied after a VAR check, they did not test the keeper until the 94th minute when Wataru Endo headed home at the far post from a corner.