It is sure to remembered for longer than their careers, which are only starting, really.
But the 21-year-old’s quest to win back-to-back titles in New York came to an end Monday when she was ousted by giant killer Belinda Bencic, 7-5, 6-4.
No one on the women’s tour has beaten more top-five or top-10 players this season than the 13th seed, and she also made it three victories in a row this year over the Japanese star, who will lose her No. 1 ranking to Ashleigh Barty.
Bencic will face Donna Vekic, who saved a match point to defeat Julia Goerges 6-7(5), 7-5, 6-3, in the quarterfinals.
Osaka entered the US Open under an injury cloud, having retired at her previous event in Cincinnati with a knee injury two weeks ago.
Was it a factor under the roof at Arthur Ashe stadium?
She is sure to shed some light in her post-match press conference, but Osaka could be seen taking a tablet when visited by the trainer at 2-3 in the second set.
It’s been that kind of last 24 hours at the US Open. On Sunday, men’s defending champion Novak Djokovic was forced to retire down two sets to Stan Wawrinka thanks to a shoulder injury the Serb had been carrying for weeks.
Bencic, 22, has had a lot of injury problems herself, so the win over Osaka could be even sweeter for her.
Like Gauff — and Vekic — she was a precocious teen. In 2015, for example, Bencic strung together a hugely impressive week to win the Rogers Cup, knocking off the likes of Serena Williams, Simona Halep, Caroline Wozniacki and Ana Ivanovic.
But then the injuries crept in. There was wrist surgery in 2017, back issues and most recently a foot complaint that forced her to retire in Cincinnati.
Bencic, however, benefited from some luck this week when third-round foe Anett Kontaveit handed her a walkover due to illness.
Bencic, who is mainly coached by her dad, Ivan, also has been extensively coached by Melanie Molitor — the mom of Martina Hingis — and exhibits similar court craft to Hingis.
That was fully evidenced in the fifth game of the second, when she beautifully redirected a venomous Osaka drive down the line with a backhand on the way to the set’s lone break.
She had drawn first blood by winning a high-quality first set where both players combined for 31 winners and only 19 unforced errors.
Osaka had clawed back from 0-2 down to level but was broken at 5-5.
Bencic has always loved New York — the site of her maiden grand slam quarterfinal in 2014 — and that certainly won’t diminish now.
Osaka’s exit proves just how difficult it is for anyone not named Serena Williams to retain the US Open women’s title. The last player to do so was Kim Clijsters in 2010.