Daria Kasatkina and Mirra Andreeva will meet in an all-Russian final at the Ningbo Open, each advancing after their opponents retired in their matches Saturday in China.

Kasatkina, the No. 5 seed, won the first set 6-4 against Spain's Paula Badosa, the No 8 seed. Badosa withdrew before the second set, reportedly because of dizziness, in a match that was punctuated by weather delays. Badosa's blood pressure was checked during the break between sets.

Andreeva was leading her match against Karolina Muchova, up 6-2, 1-0, when the Czech called it quits. Muchova took a medical timeout before the second set and returned to the match for a game and one point before retiring, reportedly with a back injury.

The 17-year-old Andreeva will play in Sunday's final well-rested. She reached the semifinal after Czech Barbora Krejcikova's retired in their quarterfinal match.

It will be the sixth singles final of the season for Kasatkina - all in WTA 500 events, in which she has a 1-4 record. Andreeva will be playing in her first 500-level final.

--Field Level Media