Coco Gauff may be saving the best for last. In what is shaping up to be potentially her best week of the season, Coco Gauff beat the world No. 1 Aryna Sabalenka in two turbulent sets Friday to set up a championship battle against the Olympic gold medalist Zheng Qinwen this weekend at the WTA Tour Finals.

RIYADH, Saudi Arabia (AP) — Coco Gauff defeated top-ranked Aryna Sabalenka 7-6 (4), 6-3 and set up a showdown with Olympic champion Zheng Qinwen in the final of the WTA Finals on Friday. Gauff generated six break points to Sabalenka’s four and built on early momentum in the opening set’s tiebreak that she carried through to the second set.

As the WTA Tour Finals round-robin stages progress, Aryna Sabalenka and Coco Gauff have qualified for the semifinals, where they are joined by Zheng Qinwen. Sabalenka was drawn with Jasmine Paolini, Elena Rybakina and Zheng Qinwen in the group stage,