Tatsuya Tanaka's second-half goal eventually proved the difference in the Group A clash at KK Wing Stadium in Kumamoto after Zaher Farid had cancelled out Shinji Okazaki's early opener.

Japan were on the front foot from the opening whistle and took the lead with just seven minutes gone.

Tanaka worked a short corner with Kengo Nakamura and the former then delivered a pass that Okazaki tapped home.

Japan almost extended their lead from another Nakamura corner in the 26th minute as Takeshi Aoki outjumped the Yemen defence but the Kashima Antlers midfielder's header sailed narrowly wide.

Having been rendered largely impotent in the first half, Yemen began the second period with more purpose and soon levelled the encounter.

Ali Al-Nono's forceful run down the right was ended prematurely by Yuichi Komano and from Ali Al-Sasi's free-kick, Farid nodded home at the back post.

Seiichiro Maki was introduced by Japan coach Takeshi Okada on the hour mark and almost made an immediate impact but his header from Nakamura's corner narrowly failed to hit the target.

However, Japan regained the lead five minutes later when Tanaka got the final touch to Okazaki's header before the latter nearly extended the hosts' lead when he twice hit the woodwork.