A rain-delayed victory moved Aryna Sabalenka to the verge of wrapping up the WTA Tour's season-ending No. 1 ranking.
Sabalenka, the top seed, completed a 6-2, 3-6, 6-3 win over fourth-seeded Elena Rybakina of Kazakhstan on Friday to clinch a semifinal spot in the WTA Finals at Cancun, Mexico.
Should Sabalenka beat second-seeded Iga Swiatek of Poland on Saturday, the Belarusian would be assured of ending the year atop the ratings.
Sabalenka, the reigning Australian Open champion, wound up with a 2-1 record in the Bacalar Group, coming in second behind fifth-seeded seeded Jessica Pegula (3-0).
The other semifinal will feature Pegula and third-seeded Coco Gauff in a matchup of U.S. players.
The final two matches in the Chetumal Group were also held on Thursday, with Swiatek completing a 3-0 run by routing sixth-seeded Ons Jabeur of Tunisia 6-1, 6-2.
Gauff took second in the group by rallying for a 5-7, 7-6 (4), 6-3 win over seventh-seeded Marketa Vondrousova of the Czech Republic.
Jabeur finished 1-2, and Vondrousova went 0-3.
Rybakina lost two of her three matches, finishing third in the Chetumal Group at 1-2. Eighth-seeded Maria Sakkari of Greece wound up 0-3.
Sabalenka led Rybakina 6-2, 3-5 when play was suspended on Thursday. Rybakina closed out the second set, but Sabalenka broke serve to open the third set and wasn't challenged after that.
"Was really tough battle in really tough conditions," Sabalenka said. "I'm super happy that I was able to get this win no matter what."
Gauff won just 1 of 11 second-serve points and just 39 percent of her service points overall in the first set against Vondrousova before her game picked up.
Gauff wound up with the win despite committing 38 unforced errors to Vondrousova's 25, a differential that wasn't offset by Gauff's 31-25 edge in winners.
"I felt like I needed to hit through the court," Gauff said. "She's a very tricky player. When you play her pace and let her move you side to side, it's tough. And I played her, it's my third time, so I know that.
"But obviously, in the wind, it's tough to be as aggressive as you want, because the bounces are weird and the ball was moving. So I'm glad I made that adjustment and didn't get too frustrated when I missed. You pay the price for hopefully a good reward."
Pegula holds a 2-1 head-to-head edge against Gauff, with the pair having split two matches this year. Swiatek and Sabalenka also have split two matches in 2023, leaving Swiatek with a career 5-3 advantage.
—Field Level Media