Former world No. 1 Naomi Osaka announced that she is no longer working with coach Wim Fessette. 

The parting of ways comes after a disappointing second round exit at the U.S. Open for Osaka. 

At Flushing Meadows, Osaka lost 6-3, 7-6 (5) to Karolina Muchova. Afterward, she said: "It’s a little rough, because I do take these losses really personally. It’s like a dramatic word, but I feel like my heart dies every time I lose."

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Karolina Muchova and Naomi Osaka embrace

Karolina Muchova (CZE) (left) after beating Naomi Osaka (JPN) on day four of the 2024 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center.  (Robert Deutsch-USA Today Sports)

This is not the first time Osaka and Fissette have parted ways.

Fissette began working with Osaka shortly before the start of the 2020 season. They had split in the summer of 2022 before teaming up again last year when Osaka returned to training following maternity leave.

The 26-year-old won two of her four Grand Slam titles while working with the Belgian coach and expressed her gratitude on her Instagram story on Friday.

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Naomi Osaka looks on

Naomi Osaka (JPN) walks onto the court prior to her match against Karolina Muchova (CZE) in a women's singles match on day four of the 2024 U.S. Open tennis tournament at Billie Jean King National Tennis Center.  (Geoff Burke-USA TODAY Sports)

"4 years, 2 Slams and a whole lot of memories. Thanks Wim for being a great coach and an even greater person, wishing you all the best."

Fissette reflected on his time with Osaka in an Instagram post of his own Saturday.

"In 15 years on tour, this was one of my best years working together with amazing people," Fissette wrote. "From every defeat, we worked harder and better and grew a lot. We were very close to a breakthrough."

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Naomi Osaka plays shot

Naomi Osaka (JPN) hits to Karolina Muchova (CZE) on day four of the 2024 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center.  (Robert Deutsch-USA Today Sports)

After the U.S. Open, Osaka "decided to move forward with a new path," he added. "I accepted it knowing we close this second run with more good memories and gratitude for building her way back."

The Associated Press contributed to this report. 

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