No.2 seed Ons Jabeur advanced to the semifinals at the Credit One Charleston Open for the third straight year when Anna Kalinskaya retired from their quarterfinal match on Friday.
Jabeur was leading 6-0, 4-1 when Kalinskaya retired due to illness. She'll next face No.3 seed Daria Kasatkina, who beat No.9 seed Madison Keys for just the second time in 10 career meetings, 6-7(5), 6-4, 6-2, in a match between two of the tournament's former champions.
Here's more about the two Top 10 players' victories, by the numbers.
5: Jabeur improved to 2-0 against Kalinskaya with the victory, and has only dropped five games in their two matches thus far. She also won 6-2, 6-2 in Indian Wells two years ago.
2: The Tunisian is through to her second semifinal of the season, and first since reaching the last four of the Adelaide International 1 in January.
3: Unseeded Kalinskaya was playing her third seeded player in four matches, as well as her first WTA 500 quarterfinal. She had previously beaten No.11 seed Anhelina Kalinina in Round 1, and No. 6 seed and former World No.1 Victoria Azarenka in the last 16.
18: Before Kalinskaya retired, Jabeur was in command. She lost just 18 points in the 11 completed games. She broke serve four times, and saved all three break points she faced -- all serving from 0-40 at 4-0 in the first set.
"I wish Anna a speedy recovery," Jabeur said after the match. "I think it was a great match for me. I think I did everything how it's supposed to be and listened to my coach, 100 percent, for the first time in my career."
11: Jabeur is bidding for her 11th career WTA final appearance. She will face the winner of the quarterfinal between No.3 seed Daria Kasatkina and No.9 seed Madison Keys in the final four.
10: Kasatkina and Keys had played nine previous times, but all of those meetings came on hard courts.
17: The two players combined for 17 breaks of serve over the course of 2 hours and 33 minutes. Kasatkina broke Keys' vaunted serve 10 times, while Keys broke Kasatkina seven times.
8: Eight of those breaks came in the first set, which lasted over an hour. Keys led 2-0 and 4-2, before Kasatkina served for the set at both 5-4 and 6-5. However, she never reached set point, and the American wrapped up a one-set lead on her third set point in the tiebreak.
12: From a set and a break down, Kasatkina won 12 of the last 14 games. She lost just three points en route to winning the last three games of the second set, and broke Keys three times in the waning stages of the decider.
7: Jabeur and Kasatkina will be playing for a seventh time, and Jabeur leads the head-to-head, 4-2. She's won the last four matches the two have played.