Coco Gauff showed supreme determination to come back from a set and a break down against Zheng Qinwen to win the season-ending WTA Finals.

In an enthralling encounter that lasted just over three hours, the American beat the Olympic champion 3-6 6-4 7-6 (7-2) in Saudi Arabia. At 20-years-old, she is the youngest player to win the tournament since Maria Sharapova exactly two decades ago, and the youngest American since Serena Williams in 2001.

"This means a lot to me," said third seed Gauff, who wins a total prize of $4.8m (£3.7m) - a record amount in women's professional tennis. "This is the first professional women's tennis event here in Saudi Arabia and I'll forever be etched in history in that standard."

Speaking earlier, she said: "That was a great match. I was just trying my best to hang in there and I never gave up."

In progressing to the showpiece in Riyadh, Gauff had become the youngest player to reach the championship match at the WTA Finals since Caroline Wozniacki in 2010. She had seen off both the world number one and two in Aryna Sabalenka and Iga Swiatek en route to the final and piled the pressure on her opponent in the early stages against Zheng.

In what was only their second meeting - Gauff having won their first in straight sets in Rome earlier this year - Zheng, 22, was forced to save four break points, including three in a captivating fifth game. But it was the Chinese seventh seed who got the decisive break in the opener, a double fault from Gauff after a hat-trick of unforced errors giving Zheng the advantage from which she sealed the set as Gauff slammed a backhand into the net.

Zheng's serve is one of her greatest weapons, but she struggled to show it off against Gauff, with her first of only four aces coming at the start of the second set after she had broken Gauff again. With renewed determination, the American restored parity in an outstanding return game, after which the pair again traded breaks.

But the unperturbed Gauff broke Zheng's serve for the third successive game to take the match to a decider. At the start of the third set, Gauff saved three break points before conceding as Zheng took back control on her serve - yet it was only temporary.

Gauff soon broke back, her fine play at the net rewarded as Zheng sent a forehand long, before securing another love hold. Zheng then won three successive games, dropping just four points along the way, and looked to be sauntering towards the win.

But a game of errors when serving for the match brought Gauff back into contention. That was the start of the American's own three-game run, her spree halted as Zheng saved two championship points to ensure the tournament would be decided by a tie-break, which Gauff utterly dominated.

The victory marks her third title of a year in which she did not reach a singles Grand Slam final, with her best runs coming at the Australian Open and on the Roland Garros clay, when she was eliminated in the semi-finals. Fourth-round exits followed at Wimbledon and in New York, where she had been defending her maiden major title from 2023.

Gauff previously said she had reservations about playing in Saudi Arabia because of the country's human rights record, but said after her win: "Hopefully there's more events here."

Although it has ended in defeat, 2024 has been a season to remember for Zheng, who after reaching her first Grand Slam final at the Australian Open in January - losing to Sabalenka - made history in Paris in the summer when she won China’s first Olympic singles tennis gold medal. In addition to that success, the year also brought Zheng a successful title defence at the Palermo Ladies Open as well as victory at the Pan Pacific Open, which secured her place at the WTA Finals for the first time in her career.

She is the youngest player to reach the final of the tournament on debut since Petra Kvitova in 2011 and will start 2025 as a top-five player. "It hurts to lose this match of course but I think it's better I forget it and move on for my next steps," said Zheng.

Earlier, second seeds Erin Routliffe and Gabriela Dabrowski won the doubles title in Riyadh. The New Zealand-Canadian pair beat American Taylor Townsend and Katerina Siniakova of the Czech Republic 7-5 6-3, avenging their loss in the Wimbledon final.