Riyadh, Nov 10 (IANS): Coco Gauff pulled off an incredible comeback to squeak past Zheng Qinwen of China 3-6, 6-4, 7-6(2) to clinch the WTA Finals trophy, her first year-ending championship title of her career.

Gauff will be rewarded with USD 4,805,000 for her week in Riyadh - the largest payout at a WTA Tour event. The American has also clinched the season-ending World No.3 ranking for the second straight year.

In her third consecutive WTA Finals appearance, Gauff needed to overcome multiple deficits to prevail over Zheng. The American had to come back from a break down in the second set, and she was twice down a break in the third set, where Zheng served for the match at 5-4. But, Gauff used her grit to battle back on each of those occasions to win her ninth career WTA Tour singles title, WTA reports.

Since the WTA Finals began in 1972, Gauff is the fourth American to win the season ending tournament before turning 21 years old, joining Chris Evert (1972, 1973 and 1975), Tracy Austin (1980) and Serena Williams (2001), according to WTA stats.

Also this week, Gauff becomes just the second American since 1990 to claim four Top 10 wins at a single event before turning 21. Lindsay Davenport first achieved that feat en route to the gold medal at the 1996 Olympics.

Gauff capped off a late-season surge with victory in Riyadh on Saturday. After a Round of 16 loss in her US Open title defense, The American rebounded, winning 12 of her last 14 matches this year.

Zheng also ended the season in hot form. Since Wimbledon, this year's Olympic gold medalist Zheng has posted a 31-6 win-loss record.