World No.1 Aryna Sabalenka on Friday triumphed over Kazakh Elena Rybakina (N.4) 6-2, 3-6, 6-3 to join Iga Swiatek in the semifinals of the WTA Masters in Cancun, Mexico.
The Belarusian, who finished 2nd in her group behind the American Jessica Pegula, thus maintains her chances of retaining her rank as world number one at the end of a match interrupted Thursday by rain while she was trailing in the second set .
When the match resumed, some 16 hours later, Rybakina equalized a set before Sabalenka won the third set and the match.
Swiatek, world No.2, then beat Ons Jabeur (N.7), 6-1, 6-2 in just 67 minutes to finish at the top of his group with a perfect record of 3-0.
US Open titleholder Coco Gauff closed out her group matches with a 5-7, 7-6 (7/4), 6-3 victory over Wimbledon winner Marketa Vondrousova to advance for the semi-finals - with his place assured after Swiatek's victory.
Gauff will face her compatriot Pegula in the semi-final, but it is the clash between Sabalenka and Swiatek which will be in the spotlight.
If Sabalenka wins, she will end the year in world No. 1, but a defeat would open up the possibility for Swiatek to regain the throne, which she had already held for 75 weeks until the US Open.
This is a rematch of last year's semifinal in Fort Worth, Texas, where Sabalenka won 6-2, 2-6, 6-1.
The two players are tied after their two confrontations this season, both on clay. Swiatek, the reigning French Open champion, won the final in Stuttgart, while Sabalenka won in Madrid.
The duel between Gauff and Pegula will be the first all-American semi-final of the event, which brings together the eight best players of the season, since the format of two groups of four was reintroduced in 2003.
J G P SG SP
1. Jessica Pegula (USA/N.5) 3 3 0 6 0 QUALIFIEE
2. Aryna Sabalenka (BLR/N.1) 3 2 1 4 3 QUALIFIED
3. Elena Rybakina (KAZ/N.4) 3 1 2 2 4
4. Maria Sakkari (GRE/N.8) 3 0 3 1 6
J G P SG SP
1. Iga Swiatek (POL/N.2) 3 3 0 6 0 QUALIFIED
2. Coco Gauff (USA/No.3) 3 2 1 4 1 QUALIFIEE
3. Our Jabeur (TUN/N.6) 3 1 2 2 4
4. Marketa Vondrousova (CZE/N.7) 3 0 3 1 6