Midfielder Shunsuke Nakamura was among the scorers for Japan, forced to qualify for the tournament after losing the third-place playoff to South Korea two years ago. The "Blue Samurai" have nine points from three matches in Group A, putting the three-times Asian Cup champions within reach of the finals in Qatar.
German-based midfielder Makoto Hasebe lashed a fierce right-foot shot into the top corner from 25 metres to put the visitors ahead in the 32nd minute.
Japan added a second goal in the 74th through a header from substitute Hisato Sato.
Nakamura curled in a free kick 10 minutes later before striker Shinji Okazaki converted a penalty in the last minute for his 15th goal in 20 internationals.
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