Up a set and a double-break on Aryna Sabalenka two weeks ago in Toronto, Coco Gauff suddenly felt herself sliding backwards.

“I was reverting back to old mentalities,” she would say later. “I got to a point where I was being too negative on myself. And I said if I was going to lose, I’m not going to lose like this.

“So I had to change. And that’s what I did.”

Gauff erased an 0-3 third-set deficit and defeated the former World No.2 in a thrilling tiebreak -- at 3 hours, 11 minutes, the longest match of her life. The day before, she failed to convert four match points in the second set, but rallied from a break down to win another third-set tiebreak against Wimbledon champion Elena Rybakina.

The 18-year-old American has already learned this sometimes elusive lesson: That giving in doesn’t mean giving up. Pursuing perfection means embracing imperfection. 

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“These are the type of players I need to have to beat if I want to win a Grand Slam,” Gauff told reporters. “So these matches are giving me more confidence. For me I needed these matches leading up into the US Open. I think you guys can see on my forehand and my serve there’s definitely been a drastic improvement.

"I think that right now I feel like I'm rising to the occasion. Whereas before I felt like I was almost crumbling to the pressure because I was trying to deflect it. 

While Gauff fell to eventual National Bank Open champion Simona Halep in the quarterfinals, she and Jessica Pegula won the doubles title. 

In the Race to the Finals, Gauff is ranked No.3 in doubles and No.5 in singles.

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The Williams effect

When the 14-year-old Serena Williams turned professional, Corey and Candi Gauff were barely out of college. Corey played basketball at Georgia State and Candi (nee Odom) ran the heptathlon at Florida State. When Williams won her first major singles title, the 1999 US Open, Coco Gauff was still more than four years from existence.

In 2009, after watching Serena win the Australian Open on television, 4-year-old Coco announced to her parents that she wanted to be a tennis player. Six year later, she began training at the Mouratoglou Academy in France, overseen by Patrick Mouratoglou, Williams’ longtime coach. Two years later in Melbourne, Williams won the last of her 23 Grand Slam singles titles. Eight months later, Gauff became the youngest US Open girls’ singles finalist ever. She was 13.

 “I grew up watching her,” Gauff said a few weeks ago in Toronto. “I mean that’s the reason why I play tennis. Tennis being a predominantly white sport it definitely helped a lot. Because I saw somebody who looked like me dominating the game. It made me believe that I could dominate, too.”

And it isn’t just a debt to Williams. Gauff was also inspired by Venus Williams, now 42. You can see elements of her game in the way Gauff plays, especially her serve. Corey Gauff, too, had an idol of sorts, a mentor from afar. His name was Richard Williams.

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After seeing the Williams’ startling success, Corey and Candi left their jobs to devote themselves full-time to Coco’s tennis career. Corey and Candi employed many of Richard’s training techniques; Corey was the primary coach and Candi was in charge of homeschooling.

“I think her whole story, the Williams sisters story, not just Serena, with Mr. Williams and all that he’s done for both of them inspired my dad to continue to coach me and help me,” Coco Gauff said. “Even though he had not really much tennis experience. But he was like, ‘If Mr. Williams can do it, then I can.’

“I think it’s not so much just what Serena and Venus have left, it’s also the whole Williams family in general.”

Six years ago, Gauff won the 12-under Junior Orange Bowl title, joining Hall of Famers Stefanie Graf (1981), Monica Seles (1985) and Jennifer Capriati (1986). Later that year, she was profiled by a national sports website, saying “I want to be the greatest of all time.”

By then, she had already met Serena three times.

The destiny of a champion

In 2018, at the age of 14, Gauff made her professional debut in a $25,000 ITF event in Osprey, Florida. Including qualifying, she won her first four matches. In a newspaper story later that year, she explained why Serena was her idol.

“She is just so competitive on the court. I have never seen her give up,” Gauff said. “Even now, when she is coming back from having a child, it is amazing to see that she is still strong. I like her serve, her forehand, her aggressiveness. She has proven that she relies on that and it is allowing her to win.

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“I want to exactly copy that.”

Gauff was discovered by casual tennis fans in 2019 when she raced through the field at Wimbledon. The 15-year-old won three qualifying matches, defeated Venus in the first round and advanced to the Round of 16, where she lost to Halep, the eventual champion. In October of that year, she won her first Hologic WTA Tour title in Linz.

The second came in 2021 in Parma, and Gauff’s biggest breakthrough came this year in Paris, when she reached the final before falling to top-ranked Iga Swiatek. Despite retiring from her first-round match against Marie Bouzkova in Cincinnati with an ankle injury, she’s a realistic threat for the title in New York.

Gauff reassures fans after injury retirement in Cincinnati

“She’s playing non-stop and she’s winning non-stop,” Halep said in Toronto. “So that’s why you don’t feel like she’s young anymore. And I feel like she’s going to be a Grand Slam champion soon. She has everything to do that.”

A more aggressive approach

She’s already one of the fastest players on tour.  

Sometimes, that has worked against her.

“I feel like everybody knows I’m fast,” Gauff said. “I’m not trying to be cocky, but it’s the truth. And I know that, too. I think sometimes I just go and just put the ball on the court because I know I can run it down. That was my old mentality.

“But now I think I’m trying to take my chances more and be more aggressive. Because playing that way would definitely get me quarterfinals or fourth round in Slams. But to get to that final moment you need to take care of those details. I think I’m slowly taking care of those details.”

She’s been buoyed by the presence of Diego Moyano, who joined her team as a coach earlier this year. Moyano worked previously for the USTA, helping to develop Tommy Paul and Reilly Opelka and, more recently, with Kevin Anderson.

“He was super positive,” Gauff said. “And it made me believe. I mean, yes, my dad is always positive about my game. But you hear it your whole life so you don’t really believe it. But having someone outside come in and say these things ... I feel like I was almost afraid to lose at one point to disappoint people

“And after every match, win or lose, he always comes to me with such a positive attitude. And I think that’s transferring into my attitude.”

Said longtime tennis broadcaster Mary Carillo: “At the French, her serve and her forehand left her. But if she develops a Venus Williams-like serve, man, imagine if she could hold serve consistently. What’s going to stop her from dominating?

“She’s got a very good sense of the court -- she has the goods. And she’s a very intelligent person, and so aware of the planet and where she fits on it.”

After beating Rybakina in Toronto, Gauff pointed to her head as she approached net. Indeed, her relentless defense and a terrific backhand are formidable resources, but her mind -- her increasingly unshakeable belief -- might just be her greatest asset. That, and the debt to Serena and the Williams family.

“The legacy that she’s left through her tennis career is something that I don’t think any other player can probably touch,” Gauff said. “I think that the legacy that she will continue to leave throughout her life is something that can inspire many more generations.”