Caroline Garcia came from a set down to beat Russia's Daria Kasatkina and reach the last four of the WTA Tour Finals.
The French sixth seed won a gruelling match 4-6 6-1 7-6 (7-5) to set up a semi-final against Greece's world number five Maria Sakkari in Texas.
Sakkari, 27, qualified by topping her group unbeaten, while 29-year-old Garcia went through as group runner-up.
Poland's world number one Iga Swiatek will play Belarusian seventh seed Aryna Sabalenka, 24, in the other semi-final.
Swiatek, 21, finishes off the group stages against American Coco Gauff, 18, who cannot progress after losing her first two matches.
Phone: (800) 737. 6040
Fax: (800) 825 5558
Website: 
Email: 
