Bencic was pushed to three sets Thursday for the first time in four matches at this tournament. She was coming off a straight-set upset of defending champion and top-ranked Naomi Osaka in the fourth round.
Bencic improved to 18-3 this year. She won her third career title at Dubai last month and her first since 2015. The 22-year-old Swiss player missed five months in 2017 after wrist surgery.