TOKYO — Defending champion Christina McHale of the United States advanced to the semifinals of the Japan Women's Open by beating third-seeded Elise Mertens of Belgium 6-4, 6-1 on Friday.

McHale next faces Zarina Diyas of Kazakhstan, who beat compatriot Yulia Putinseva 4-6, 6-1, 6-3.

Also, Miyu Kato of Japan beat Aleksandra Krunic of Serbia 6-1, 6-3 and will face Jana Fett of Croatia, who knocked out top-seeded Kristina Mladenovic this week. Fett beat Wang Qiang 6-3, 4-6, 6-3.