World number one Aryna Sabalenka defeated Elena Rybakina 6-2, 3-6, 6-3 in a rain-disrupted group match on Friday to reach the semi-finals of the WTA Finals.
The Belarusian, who finished second in her group behind unbeaten American Jessica Pegula, kept her bid for the year-end number one ranking on track with a victory that took two days to complete.
She had won the first set but was trailing in the second when play was halted Thursday night after multiple rain delays.
Some 16 hours later, she and Rybakina returned to the outdoor hardcourts in Cancun, where fourth-ranked Rybakina of Kazakhstan calmly served out the second set to level the match in a matter of minutes.
Australian Open champion Sabalenka dug deep to halt Rybakina’s momentum in the opening game of the third set, surviving nine deuces and two break points to hold serve.
She used a pair of ferocious forehands to break Rybakina in the fourth game.
If Sabalenka wins her semi-final match on Saturday, she’s assured of finishing the year at number one.
If she falls, she’ll open the door to Poland’s Iga Swiatek — who topped the rankings for 75 weeks but dropped from the summit after the US Open.
Swiatek was in action later Friday closing out group play against Tunisian Ons Jabeur.
US Open champion Coco Gauff takes on Marketa Vondrousova with all four players in that group still technically in the hunt for semi-final berths.