OSAKA, Japan (AP) Defending champion Samantha Stosur advanced to the semifinals of the Japan Women's Open by beating Yulia Putintseva of Kazakhstan 6-4, 6-1 Friday.
Stosur, a two-time champion in Osaka, had nine aces. She will next face third-seeded Elina Svitolina of Ukraine, who beat Lauren Davis of United States 6-2, 6-4.
American teenager Madison Keys, one of the favorites for the title, retired from her match against Luksika Kumkhum of Thailand with a shoulder injury while trailing 6-2, 4-3.
Fifth-seeded Zarina Diyas of Kazakhstan rallied to beat Ana Konjuh of Croatiam 6-7 (4), 6-4, 6-2 and will next face Kumkhum.