Coco Gauff defeated top-ranked Aryna Sabalenka 7-6 (4), 6-3 on Friday, setting up a showdown with Olympic champion Zheng Qinwen in the final of the WTA Finals.

Gauff generated six break points to Sabalenka’s four and built on early momentum in the opening set’s tie-break that she carried through to the second set.

She’s the youngest player at 20 to make the final at the WTA Finals since Caroline Wozniacki in 2010. Zheng earlier defeated Wimbledon champion Barbora Krejcikova 6-3, 7-5 to book her place in Saturday’s final.

Zheng continued her remarkable season by reaching the decider in her first appearance. The Chinese player has won 31 of her 36 matches since Wimbledon, more than anyone else on the tour.

Zheng struck nine aces as she defeated a tired-looking Krejcikova in an hour and 40 minutes.