Coco Gauff began her bid for a second US Open title with a nerveless win over Zeynep Sonmez.
The American fourth seed, champion in 2023, was tested in the second set by Turkish outsider Sonmez but came through 6-3, 6-4.
She said: “I was nervous in the tunnel, and then for some reason when the warm-up started, it went away. I think it showed the first game how I came out serving really well.
“I don’t know what put my mind at ease. I think just maybe the confidence I had this week and knowing, like, you know, the opponent would have to play a really high level and me a really low level, maybe for it to not go my way.
“But Zeynep brought that high level today. Yeah, I was just happy to get out of that second set.”
Second seed Elena Rybakina also advanced after beating teenage American wild card Thea Frodin 6-3, 6-2.
Frodin once played Serena Williams’ double in the tennis scenes during the Oscar-winning film about the lives of Serena and her sister Venus, King Richard, starring Will Smith.
She said: “I actually have not met her yet. But hopefully I can get the chance soon to get the opportunity to meet her.
“I saw that Will Smith reposted one of my posts, so that was pretty cool and a cool experience.”
Switzerland’s Belinda Bencic was fortunate to avoid being defaulted after whacking a ball into the crowd.
The 29-year-old, seeded 12th, swatted a ball in frustration after losing a point, and then turned in horror after realising where it had flown.
She raised her arms in apology and was given a warning by the umpire, but opponent Yulia Putintseva clearly felt the punishment should have been harsher.
However, Kazakhstani Putintseva eventually won the match over three sets to send Bencic packing anyway.
In the men’s draw, fifth seed Flavio Cobolli needed five sets to see off Argentinian Francisco Comesana, while ninth seed Taylor Fritz – one of the big hopes for a home success in New York this year – beat fellow American Darwin Blanch in three.
Frenchman Gael Monfils, who retires at the end of the year, celebrated his 40th birthday in style with a 2-6, 6-2, 6-1, 6-0 victory over Adolfo Alvarez.
A late-night marathon on Arthur Ashe Stadium saw Alexander Zverev narrowly avoid becoming only the fourth top-seeded man to lose in the first round of a grand slam in the open era.
The German, who won the French Open and reached the Wimbledon final this year, trailed Italian Lorenzo Sonego by two sets to one.
But Zverev clawed his way back and eventually won in five, 6-4, 3-6, 6-7 (7,) 7-5, 6-4.
The four-hour-and-53-minute slog finished at 1.55am local time.
Arthur Fery’s hopes of making a splash were ended in the first round after a straight-sets defeat by Lorenzo Musetti. The 24-year-old had been riding on the crest of a wave since his historic run to the Wimbledon semi-finals as a wild card earlier this summer.
But he ran aground against Italian 13th seed Musetti in a comprehensive 6-3, 6-3, 7-5 loss on Grandstand Stadium.