NEW YORK — A year ago, still on maternity leave and still unsure when she would play elite tennis again, Naomi Osaka visited the US Open to appear with Michael Phelps for a discussion about mental health. While at the site, she sat in the stands to watch one of Coco Gauff's matches.

Osaka was already thinking about being back on a court at Flushing Meadows, so much so that she was pondering what she might want to wear to compete. And, there she was Tuesday, in Louis Armstrong Stadium, overpowering No 10 seed Jelena Ostapenko 6-3, 6-2 while decked out from her visor to her dress, to the bows on her back and attached to her shoes, in lime green — the color of this year's "Brat summer", inspired by British singer-songwriter Charli XCX. More importantly, she was playing very much like a two-time US Open champion and a former No 1-ranked star.

"I feel like being able to be a part of (designing) my tennis outfits gives me, I would say, a different strength, especially the US Open outfits. I feel like they are a little bit more flamboyant. When I was putting on my outfit today, I was, like, 'ah, I hope this isn't too much,'" Osaka said with a smile. "Because I had the tutu, and then I had the bow jacket and it was green. I feel like everyone was staring at me."

Another player asked for a photo, Osaka said, adding: "I hope it was a positive picture (and) it wasn't, like, 'oh, my God, look at her.' For me, when I put on the outfit, it's almost like a super suit, so I try to channel that."

She did that well enough on Tuesday to register her first victory against a top-10 opponent in more than four years.

Osaka claimed titles in New York in 2018 and 2020, along with a pair of trophies at the Australian Open in 2019 and 2021, and her matchup against 2017 French Open champion Ostapenko marked the first time that two past major champs faced off in the opening round at the US Open since Serena Williams defeated Maria Sharapova five years ago. Another such contest came Tuesday night, when 2020 Australian Open champion Sofia Kenin beat 2021 US Open winner Emma Raducanu 6-1,3-6, 6-4.

"Having two wins here means a lot, and I think for me, I've been struggling with confidence throughout the year," said Osaka, who returned to action at the Australian Open in January, her first Grand Slam appearance in nearly one-and-a-half years because of mental health breaks and time away to have a baby.

"This time now forces me to look in the mirror and say, 'hey, you've done really well here. There's no reason why you can't do well again.'"

How's this for doing well? Osaka did not make a single unforced error in the first set and finished with only five, 16 fewer than Ostapenko.

"I do remember thinking, 'I need to win this match so I can wear my other color'. That was very important to me," said Osaka, who is ranked 88th and received a wild-card invitation from the US Tennis Association. "I guess you'll see my other color next time."

Next time will be Thursday, when she faces off against 2023 French Open runner-up Karolina Muchova, who ran out a 6-3, 7-5 winner over Katie Volynets of the US.

Wang advances

Wang Xinyu was the only Chinese winner on Tuesday, after edging past Australian Arina Rodionova in three sets, 3-6, 6-4, 6-1.

Three other Chinese women, Wang Qiang, Zhang Shuai and Zheng Saisai, all playing via protected rankings, lost to Liudmila Samsonova of Russia, Ashlyn Krueger of the US and Jessika Ponchet of France, respectively.

Zhang Zhizhen, who partnered with Wang Xinyu for the Paris Olympics mixed doubles silver medal, retired with a left leg injury in the third set in his match against Briton Jack Draper, who was leading 6-3,6-0, 4-0.

Another former US Open women's champion also left early.

Bianca Andreescu, the 2019 winner, lost in three sets to sixth-seeded Jasmine Paolini, 6-7 (5), 6-2, 6-4.

Other women moving into the second round included No 1 Iga Swiatek, who got past Kamilla Rakhimova 6-4, 7-6 (6) by taking the last five points after needing to erase a trio of set points because she trailed 6-3 in the tiebreaker, and past major champions Elena Rybakina and Caroline Wozniacki.

No 11 Danielle Collins' Grand Slam singles career ended with a 1-6, 7-5,6-4 loss to Caroline Dolehide in an all-American matchup. The 30-year-old Collins is retiring after this season.

Agencies