Coco Gauff secured her place in the semi-finals of the WTA Finals in Riyadh by defeating defending champion Iga Swiatek 6-3, 6-4, marking only her second victory over Swiatek in 13 encounters. This win also confirms Aryna Sabalenka as the year-end world number one. Swiatek, who appeared rusty after a two-month hiatus, must win her next match against Jessica Pegula to have a chance to advance, dependent on Gauff's performance against Barbora Krejcikova. Krejcikova improved her standings with a 6-3, 6-3 victory over Pegula, eliminating the American from contention. Gauff's victory is a significant achievement, especially considering her previous struggles against Swiatek, who had dominated their past matches. The final round-robin matches are set to be crucial for the remaining players aiming for a semi-final spot.