Mirra Andreeva and Daria Kasatkina will meet for the Ningbo Open title on Sunday, after they each advanced to the season's penultimate WTA 500 final following semifinal retirements on Saturday.

Ningbo: Scores | Draws Order of Play

In the day's first semifinal, No.5 seed Kasatkina moved into the championship match when No.8 seed Paula Badosa retired due to dizziness directly after Kasatkina won a 6-4 first set.

"I feel sorry for Paula and I wish her all the best," Kasatkina said afterwards. "It’s never easy to finish a match like this, especially in the semifinals."

After a lengthy postponement due to rain, Kasatkina and Badosa took the court and played an opening frame which featured two further rain interruptions. Kasatkina won the last three games of that set before Badosa ended the clash between the former Top 10 players.

Kasatkina is into her sixth singles final of the year, and all of those 2024 finals have come at WTA 500 events. Kasatkina won the title on the grass of Eastbourne and finished runner-up on the other occasions.

"Of course, it’s been a great season already, I’m going to play another final tomorrow," Kasatkina said. "It feels great that I was able to go through this season very consistent, and so far healthy and stuff. It’s something that I appreciate so much."

Andreeva awaits: In the late semifinal, 17-year-old Andreeva advanced when former Top 10 player Karolina Muchova retired from their encounter. Andreeva was leading 6-2, 1-0 when Muchova stopped play due to a back injury.

"That’s not how I would like to finish the match," Andreeva said afterwards. "I’m just happy the way I managed to play the first set. Of course I just hope it’s nothing too serious, and we can see [Muchova] back on court soon."

Currently ranked a career-high No.19, Andreeva is seeking the second and highest-level WTA title of her burgeoning career. She is 1-0 in WTA singles finals thus far, having captured her maiden tour-level title on the clay of WTA 250 Iasi this summer.

"[Coach Conchita Martinez] told me, ‘Well, Mirra, you gotta be patient today,'" Andreeva said, at the end of her rainy Saturday. "I think we waited around five hours before I [went] to warm up before my match.

"We played some Uno, it was the longest Uno game that we've played, I think. We played for one hour -- and I won in the end."

Mirra Andreeva's best backhands from the Ningbo semifinals

On Saturday, Andreeva fired a number of backhand winners down the line, including on multiple second-serve returns, to power through the early stages of the semifinal. Andreeva had nine winners to Muchova's three in the first set.

A hampered Muchova took a medical time-out for her back after the first set, and the 2023 Roland Garros finalist could only contest one more game before retiring.

Head-to-head kicks off: Sunday's final will mark the first meeting between Andreeva and Kasatkina.

"I know that tomorrow’s going to be a great match," Andreeva said. "[Kasatkina] is a fighter, she’s won her last matches fighting. And of course, I think we’re kind of good buddies, so that’s going to be a hard match mentally and physically as well."