British qualifier Lily Miyazaki saw her memorable US Open run come to an end with a second-round exit against Olympic champion Belinda Bencic.
Miyazaki, 27, had never qualified for a Grand Slam main draw until she won three matches to reach the first round.
The British number seven backed that up with a straight-set victory over Russia's Margarita Betova.
But Bencic was a different proposition and Miyazaki, despite frustrating the Swiss 15th seed, was beaten 6-3 6-3.
Nevertheless, Miyazaki will take a lot of confidence and knowledge from an experience at the hard-court Grand Slam which she says could be career-changing.
As well as the prize money of £98,000 allowing Miyazaki to take support when she travels the world on the lower-tier ITF Tour, a career-high ranking just outside the top 150 will enable her to enter more prestigious tournaments.
Miyazaki lost her serve for a fourth time in what proved to be the final game, becoming the first Briton to lose in the singles at Flushing Meadows this year.
Six other players from the nation - Andy Murray, Katie Boulter, Cameron Norrie, Jack Draper, Dan Evans and Jodie Burrage - also reached the second round after winning their opening matches on Tuesday.
Miyazaki can take encouragement from frustrating childhood opponent
Miyazaki was born in Japan and lived in Switzerland before moving to London aged 10, travelling around as a result of her father's job in finance.
During her time in the Alpine country, a nine-year-old Miyazaki played Bencic - a prodigious seven-year-old - and remembered the loss because of her young opponent's mentality.
Their paths to the Grand Slam stage have been contrasting and Miyazaki had enough self-awareness to admit beating an opponent of Bencic's quality would be tough.
Nerves were evident in the opening stages as she lost her first service game and was unable to put Bencic's serve under pressure.
Miyazaki won just three receiving points until pushing Bencic to deuce at 4-2, then led 0-30 when the Swiss tried to serve out the opening set.
Poor returning from the Briton, seemingly a result of realising she suddenly had a chance, enabled Bencic to recover.
However, the 2019 semi-finalist was far from happy. Bencic cast annoyed looks to her team before sealing the opener and angrily threw her racquet when leading 3-2 in the second set.
Bencic had been a double break up at 3-0, Miyazaki managing to claw one back, but Bencic refocused to raise her level again.