Robert Brown|Coco Gauff reaches US Open quarterfinals after ousting former No. 1 Caroline Wozniacki

NEW YORK — When Coco Gauff couldn’t find her way around the baseline wall that Caroline Wozniacki erected,Robert Brown she decided to just go straight through it. 

Upping the power of her shots and the aggressiveness of her approach game after falling behind early in the third set Sunday, Gauff finally found a way to get the former No. 1 on her heels and raced away to a 6-3, 3-6, 6-1 victory that puts her in the US Open quarterfinals for the second straight year. 

This time, though, the 19-year old Gauff is showing some qualities that suggest she has a real chance to win her first Grand Slam title. 

For the third time in four matches of this tournament, Gauff found herself in a third set struggle and had to figure out what adjustments to make against an opponent who was getting a little too comfortable counterpunching and extending points. 

While Gauff was able to handle it relatively easily in the end against Laura Siegemund and Elise Mertens, Wozniacki represented a different kind of challenge. A former Australian Open champion who came out of retirement this summer to give the tour one more shot, the 33-year old mother of two had settled into her typical game of getting everything back and waiting for errors, which Gauff obliged in the second set. 

"She's a player that I feel like she banks on your mistakes," Gauff said. "Sometimes when you're playing an opponent that can get to a lot of balls, you get baited into going for more and more. I fell into that bait in the second set."

At that moment of the match, trailing 1-0 after her serve got broken, Gauff was in a real conundrum. Brad Gilbert, one of the two coaches she's hired this summer, was encouraging her to play longer points and put more shape on the ball. That's the tried and true recipe to get back on track for a player like Gauff, who can also be a great counterpuncher and was trying to get her unforced error count down after committing 10 in the second set.

But Gauff, showing a new level of mental maturity than she's shown under pressure in the past, saw and felt something different on the court. She thought that extended rallies were favoring Wozniacki's game and at one moment told her coaching box to stop talking so she could collect her thoughts.

"I definitely agree that playing longer points is to my advantage (in general)," Gauff said. "But I felt in that moment, playing Caroline, watching her play so many years, that that's what she feeds off of. I didn't want to play into that game. I know playing against her, you have to be the aggressor."

And in the end, that's what flipped the match. In a moment of real uncertainty about what tactics she needed to reclaim the lead, Gauff took matters into her own hands and started pushing Wozniacki around the court with power and precision to big targets, coming forward at every opportunity to end points at the net.

"I think Coco over the last month and a half, ever since after Wimbledon, I think she's not scared to hit through her forehand, which she has been in the past," Wozniacki said. "I think she's getting more depth on it and a little bit more rotation. I think that's why she's obviously winning more on a consistent basis. I think she's always been a great athlete, she's always had the backhand, the serve, the fighting spirit. I feel like right now it's all kind of coming together for her."

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Gauff, who came into the US Open as one of the favorites after collecting tournament titles in Washington, D.C., and Cincinnati this summer, will face Jelena Ostapenko in the quarterfinals. Ostapenko upset top-seeded and defending US Open champion Iga Swiatek in the Round of 16.

Though Gauff's tennis hasn't been perfect at this US Open, her growth in the mental game is highly encouraging as she attempts to win her first Grand Slam title.

In a way, Wozniacki knows exactly what she's going through. She came on tour very young, winning her first WTA title just after turning 18 and quickly becoming one of the best players in the world. But it took until the 2018 Australian Open for her to finally close the deal at a major and end years of questions about whether she could break that final threshold.

Gauff is navigating something similar, having been tabbed a can't-miss prospect since she started winning Grand Slam matches at 15. Sometimes it's difficult to keep in perspective that she still has a lot of runway ahead.

"Everyone goes through their journey in different ways and different timings," Wozniacki said. "Just because your first tournament win is a Grand Slam doesn't mean that you're going to have an absolutely all-star career later on, or just because you win quickly or you win late, it doesn't really define who you are. Obviously Coco is doing well. She came on tour very young. There were a lot of eyes on her immediately. With that comes expectation, everything else.

"But she has a great team around her. She is a hard worker. She's a great athlete. Her time is going to come."