Masanaga Kageyama made ten changes to his starting eleven from their previous game, with only Hirokazu Ishihara being the unchanged member of their squad, but Japan showcased the depth of their bench strength with a dominating performance against Iraq.
Qahtan Chathir Drain Al-Rubaye made two changes to his starting eleven with Ali Safaa and Ali Mohsin coming in for Mahdi Hameed and Ahmed Sartip.
Group B: Japan defeat Iraq 5-0
(JPN: Yuta Taki 10', Kyosuke Tagawa 27', Taichi Hara 34', 77’, Koki Saito 85')
Japan changed from a 4-4-2 to a 4-3-3 formation with Takuya Ogiwara and Hirokazu Ishihara controlling the wings while Yuta Taki forged himself as a striker. The Blue Samurais had 18 attempts on goal, of which eight were on target and nine were off the mark.
Iraq, who started with a 4-2-3-1, changed to a 4-3-3 formation. Hasan Abdulkareem and Moamel Abdulridha moved forward to support the lone striker. The Mesopotamian Lions, looking for their second consecutive quarter-final appearance, had four shots finding the target from their 12 attempts.
Iraq squandered an early opportunity when Hasan Abdulkareem's effort got denied by goalkeeper Keisuke Osako in a one-on-one situation.
Shimizu S-Pulse's Yuta Taki came up with a clever backheel to score the opener for Japan after Takefusa Kubo stretched the defense before crossing it to the center of the goal.
Tagawa cracked another effort into the upright from a Yuta Taki cross.
Japan scored their second after a cross from Takuya Ogiwara had Takefusa Kubo jumping at the last minute to deceive the goalie, for Sagan Tosu striker Kyosuke Tagawato to come up with a fierce right-footed strike to find the bottom left corner.
With Kyosuke Tagawato letting the ball go through his legs, Taichi Hara made it 3-0 with a spectacular strike from 20 yards out with the assist coming in from Hirokazu Ishihara.
The Blue Samurais hit the post once again through Yuta Taki's effort, following which Takefusa Kubo rattled the woodwork to deny a fourth for Japan.
Their fourth goal came courtesy of a glancing header from FC Tokyo's Taichi Hara, who got in front of his marker Hasan Raed. Koki Saito was credited with the assist from a corner-kick.
Yokohama FC striker Saito dribbled past two defenders to finish with a right-footed strike to the bottom left corner from Takuya Ogiwara’s pass to score the fifth.
Japan demonstrated their intentions of defending their title with a clinical display in the group stages, topping their group with ease. They will be meeting hosts Indonesia in their quarter-final clash. Iraq would be disappointed at finishing last, and more importantly, ending their campaign without a victory.
Group B Standings: Japan 9, Thailand 4, North Korea 3, Iraq 1