Bertens won 6-3, 0-0 after Naomi Osaka retired due to injury in her third round robin match in Singapore on Sunday.

Bertens won 1-6, 6-3, 6-4 over Angelique Kerber in her first round robin match in Singapore on Monday.

Bertens lost 7-5, 2-6, 7-6 (3) to Margarita Gasparyan in the second round of Linz on Thursday.

Bertens won 6-2, 6-1 over Barbara Haas in the first round of Linz on Wednesday.

Bertens lost 6-4, 6-2 to Anastasia Pavlyuchenkova in the second round of Wuhan on Tuesday.