Qualifier Zarina Diyas wrapped up a stunning week at the Japan Women's Open by securing her maiden WTA title with a straight-sets victory over Miyu Kato.

The Kazakh, who overcame defending champion Christina McHale in the last four, triumphed 6-2 7-5 in Tokyo on Sunday.

Ranked 100 in the world – still 71 places above her opponent – Diyas denied the home crowd a Japanese success, securing the win with two breaks in each set, dropping serve only once.

Kato was also looking for her first WTA crown, with her scalps en route to the final including that of fourth seed Kristyna Pliskova.