CNN
—

Coco Gauff stunned world No. 1 Aryna Sabalenka in the semi-finals of the WTA Finals on Friday, becoming the youngest player since 2010 to reach the final of the tournament.

The 20-year-old American ultimately came out on top in a back-and-forth match, beating Sabalenka 7-6 (4) 6-3 in Riyadh, Saudi Arabia, fighting back twice after being in the suffered a slump in the first match. set.

She will now face China’s Zheng Qinwen for the title and the chance to become the youngest player since Maria Sharapova in 2004 to win the prestigious season-ending tournament reserved for the world’s best players.

Gauff is already the youngest player to beat the reigning world No. 1 at the WTA Finals since Maria Sharapova beat Lindsay Davenport in 2004, according to the WTA.

And in a nice symmetry, Gauff and Zheng, 22, are the youngest pair to appear in the final since 2004, when a 17-year-old Sharapova defeated a 23-year-old Serena Williams.

According to Opta, Gauff is also the youngest player to defeat the reigning number 1 and number 2 in the world during the WTA Finals since Kim Clijsters in 2002.

“I asked (about the record) as soon as I got the match,” Gauff said, according to the WTA. “I asked, ‘Was this the youngest? It must be some kind of record.’ I asked the Sky team what the answer was. They didn’t have one, but that’s good to know.

“It was 2004. The year I was born was the last time, so I’ve never actually seen it in my life. That’s pretty cool. It shows that age is a number in both directions, old and young.”

Sabalenka broke her early in the first set, but the American immediately returned the favor, before Sabalenka broke again at 5-5 to give herself a chance to serve for the set.

But the Belarusian, who made several uncharacteristic unforced errors throughout the match, squandered the opportunity and Gauff went on to win the opening set tiebreak.

The American then raced to a 4-1 lead in the second set and although Sabalenka fought hard twice to break back, she closed the match with her sixth break of the match.

She will next face a tough opponent in Zheng, the newly crowned Olympic champion who has won 31 of her last 36 matches since Wimbledon.

The Chinese star defeated Wimbledon champion Barbora Krejčíková in the semi-finals to become the youngest player to reach the final in her debut at the tournament since 2011.