NEW YORK -- Caroline Wozniacki's resurgent run at the US Open ended in the fourth round after a 6-3, 3-6, 6-1 loss to No.6 Coco Gauff. The former No.1 leaves New York confident that her decision to return to competition after three years was the right one. 

Gauff fights off Wozniacki to make US Open quarterfinals

Wozniacki retired after the 2020 Australian Open to start a family with husband David Lee. She returned to the Hologic WTA Tour this summer at tournaments in Montreal and Cincinnati, and proved her competitive resilience and quality to make her first Slam fourth round since winning the 2018 Australian Open. 

"I wanted to see with these three events that I came back and played this year, I wanted to see kind of where I was tennis-wise, where I was physically and everything else," Wozniacki said. "I think I've learned a lot from that.

"I think I'm exactly where I want to be. There's still a few things that I want to work on and I can do better. But in general I think it's very positive. I think every event that I played, I played a little better. Every match I played here, I played a little bit better each time. A lot of positives I can bring with me."

Making the Round of 16 and pushing 19-year-old Gauff to three sets has buoyed the Dane's confidence. 

"Obviously I think my experience makes me believe that even if I'm not playing week in, week out, that I can still go out there and play my best tennis when I'm out there on court.

"I am encouraged. I think my game is pretty good. I think that I can beat anyone on any given day. I also believe if I'm not playing my best, I can also lose today."

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Wozniacki felt her serve ultimately let her down against Gauff. She served at 57 percent first serves in and was broken five times in the match. But throughout her tournament, Wozniacki's fitness and court coverage left an indelible mark on the competition. Her back-to-back three-set wins over Petra Kvitova and Jennifer Brady were a gritty reminder of her competitive instincts and never-say-die defense.

Gauff was certainly impressed. If Wozniacki continues playing through the end of the season, Gauff is convinced she'll be seeded by the time the Australian Open rolls around in January.

"Usually with most players I know that I can outlast them," Gauff said. "Today I was confident that I could against her, but [at the] beginning you're thinking she's [just] coming back, maybe she'll get tired. I didn't feel that at all.

"I think really I just started to raise my level. But I don't think the match was based off the fitness of her getting tired, whereas some of my opponents hit a wall. Today I think I just played better."

Wozniacki said her three-tournament run makes her want to return to the practice court to continue fine-tuning her game. 

"I've always been a competitor," she said. "I've always been a hard worker. Regardless if I've been winning a lot or not, I've been working extremely hard to just try and become a better tennis player.

"That doesn't change now. I may be older, but at the same time I'm still a competitor and I want to work really hard so that I can be the best possible version of me as a tennis player when I go out on the court."