Maria Sakkari secured the eighth and final place at the WTA Finals after defeating Veronika Kudermetova 6-1 5-7 6-4 to reach the semi-finals at the Guadalajara Open on Friday.
The WTA Finals – which is contested by the women who finish top-eight for the season in ranking points – already had seven entrants locked in, with the eighth to be decided by the winner between world number six Sakkari and world number 12 Kudermetova.
Sakkari's ability to fight her way out of tough situations proved to be the difference as she saved 14 of the 15 break points she faced, while converting three of her nine chances. In the deciding third set, Sakkari made the most of her only break point, while saving all five of Kudermetova's chances to get back into the contest.
She will play Marie Bouzkova in the semi-final after the unseeded Czech was the beneficiary of Anna Kalinskaya's injury retirement in the first set, with Bouzkova leading 5-2.
It continues a terrific run of form for the 24-year-old Bouzkova, who is 19-3 in her past 22 matches, with her only losses in that span coming against world number 20 Karolina Pliskova, Wimbledon champion Elena Rybakina and world number two Ons Jabeur.
On the other side of the draw, Jessica Pegula breezed through the challenge of Sloane Stephens to win 6-2 6-2, which would have set up a tantalising all-American matchup against her doubles partner and rising star Coco Gauff, but she could not hold up her end of the bargain.
Gauff fell 7-6 (7-2) 4-6 6-3 to Victoria Azarenka, giving the Belarusian her third consecutive top-20 win after earning her spot in the quarter-final with victories over world number eight Paula Badosa and world number 15 Madison Keys.