Naomi Osaka just made a heartbreaking admission about her US Open win over Serena Williams.

US Open champion Naomi Osaka has qualified for the WTA Finals in Singapore for the first time.

The 20-year-old Japanese player becomes the third woman to book her place at the season-ending event later this month, joining world No.1 Simona Halep and Wimbledon champion Angelique Kerber.

The remaining five players will be confirmed over the last three weeks of the regular season, with the WTA Finals beginning on October 21.

Osaka established herself as a contender for the big titles by winning in Indian Wells in March and then produced a stunning run in New York, culminating in a dramatic victory over Serena Williams to win her maiden slam title.

Osaka’s achievement, becoming the first Japanese player to win a slam singles title, was overshadowed by the row between Williams and umpire Carlos Ramos, and the 20-year-old told media at the China Open that the memory feels “bittersweet”.

She said: “There’s a lot of stuff I want to say about how I felt. For me, I don’t know, the memory of the US Open is a little bit bittersweet.

“The day after, I really didn’t want to think about it because it wasn’t necessarily the happiest memory for me. I just sort of wanted to move on at that point.”

Osaka, ranked sixth, has been in fine form since lifting the trophy at Flushing Meadows, immediately reaching another final on home soil at the Pan Pacific Open.

She has good memories of Singapore having won the rising stars event played alongside the main finals in 2015.

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