Coco Gauff became the youngest player to win the WTA Finals in 20 years after edging Olympic champion Qinwen Zheng in an epic season-ending finale.

Gauff, who was two points from defeat, sealed a stunning 3-6 6-4 7-6 (7-2) victory against Olympic champion Zheng in one of the matches of the year.

The former US Open champion, who struggled during the North American hard-court swing, turned her fortunes around by playing some of the best tennis of her career to defeat defending champion Iga Swiatek before upsetting an out-of-sorts Aryna Sabalenka en route to the final.

Gauff became the first American champion since Serena Williams 10 years ago and the youngest winner at the end-of-season event since Maria Sharapova in 2004.

The 20-year-old came from 2-0 and 5-3 down in the final set and was two points from defeat at one stage.

But she took the set to a tie-breaker, winning the first six points, and although Zheng threatened a comeback it was Gauff who sealed victory with a forehand winner at the net after three hours and four minutes of intense action.

“It was a really great match. Qinwen played some unbelievable tennis,” Gauff told Sky Sports Tennis. “I was just trying my best to hang in there and I never gave up.

“I was just telling myself, ‘It’s another point, another chance’. I’ve been in situations like this in the past and have been able to turn it around… and was able to do it again.”

Zheng was looking to complete a season in which she reached a Grand Slam final for the first time at the Australian Open and delivered China’s first Olympic tennis singles gold medal.

Gauff thanked her team and family during her on-court speech, saying: “I’d to thank my team. It’s been a long season. I want to say thank you. This week has been so fun. Win or lose, I always have a good time with you guys.

“Thank you to my parents. My mum is here. My dad is watching at home… my brother… my grandparents. Thank you to the man above for allowing me to be here.”

Zheng: I wish for better in the future

“I want to say thank you to everyone who came tonight and enjoyed this tennis match,” said runner-up Zheng.

“And thank you to my team, you try to keep me healthy. I’ve been through a lot of matches this year, but am still out on court fighting. I wish it to be better in the future.

“Congrats to the champion. It’s the first time you are champion here and I wish you a great future.”

‘Gauff has the heart of a champion’

“It’s incredible. And we can do deep dives into players’ techniques but, at the end of the day, that just epitomises the desire and heart of a champion,” said Tim Henman.

“She should have lost on numerous occasions. She just refuses to give in and it’s that resilience, added to her athletic ability, that is phenomenal. She is a very worthy winner.”

‘Gauff a very deserving winner!’

“That was such a fun match to commentate on. There were so many twists and turns… but there was one thing that was consistent, and that was Coco’s attitude,” Laura Robson said.

“She just never gave in, never let anyone see her sweat. Every changeover, every time she faced a break point, it was the exact same response.

“I have just a huge amount of respect for both players. And a very deserving winner.”

WTA Finals roll of honour

What’s coming up on Sky Sports Tennis?

• Nitto ATP Finals, Turin – (November 10-17)