Coco Gauff reacts after a winner against Anastasia Potapova during...

Coco Gauff reacts after a winner against Anastasia Potapova during their first round match in the 2019 U.S. Open on Tuesday, Aug. 27, 2019. Credit: Joseph D. Sullivan

There was nothing 15-year-oldish about it.

Coco Gauff, showing the composure of a player twice her age, battled back to win her U.S. Open debut Tuesday with a 3-6, 6-2, 6-4 victory over Anastasia Potapova.

Gauff is the first 15-year-old to win a singles match at the U.S. Open since the American CiCi Bellis in 2014.

The teenager from Delray Beach, Florida, was clearly a fan favorite when she took the court against the 18-year-old Russian.

Gauff captured the heart of tennis fans at Wimbledon earlier this summer when she defeated Venus Williams and made it to the round of 16. Tuesday, she credited the fans in Flushing for helping her survive a two-hour battle against Potapova.

“Honestly, it’s because of the crowd,” said Gauff. “You guys were amazing. No matter where I was on the court, I could hear somebody supporting me.”

Later Gauff admitted that she was nervous at the start of the match.

“This is my first main draw U.S. Open, I’m playing on Louis Armstrong, second biggest court,” she said. “After the first set, I was kind of like I have to reset, stop thinking about what would happen after the match, just think about what I need to do to win the second set.”

Gauff came back from being down a set and a break to take control of the match. She also survived a temporary momentum shift in the third set when Potapova, down 4-1, took a medical break to have her shoulder examined.

All through the final set, Gauff endeared herself to the crowd by pumping her fist after big points and talking to herself after tough breaks. She also had the very visible support of her parents Corey and Candi, who stood and cheered after every point.

“I think I gave them a heart attack,” Gauff said. “Especially my mom.”

Gauff, ranked 144th in the world, was a wild card entry and the youngest player in the draw. Since her run at Wimbledon, the American teenager has met Michelle Obama, appeared on the cover of Teen Vogue and reignited debates about the WTA’s age eligibility rule, which restricts the number of professional tournaments teens can play based on their age.

Gauff won’t be 18 for three more years, but according to Forbes will make at least $1 million from endorsements she signed before making it to the round of 16 in Wimbledon. Gauff has endorsements with the Italian pasta company Barilla, and multi-year sponsorship agreements with New Balance and the racquet company Head.

Expect more to follow. Everyone wants a piece of the next big thing, the player who will step up to fill the void in American tennis when Venus and Serena Williams retire after dominating the sport for two decades. Gauff, at this point, is a marketer’s dream, a player with style, personality and big ambitions.

Gauff will next face Hungarian Timea Babos on Thursday before a potential meeting with world No. 1 and defending champion Naomi Osaka in the third round.

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