Coco Gauff was forced to battle back from a set down as the US Open served up an unexpected and testy thriller under lights on opening night.
American title hope Gauff, the sixth seed, was left frazzled by German qualifier Laura Siegemund's incredible anticipation and volleying in the first set before finally triumphing 3-6 6-2 6-4 victory in two hours and 51 minutes.
The match swung after an epic 26-minute first game of the second set - a minute longer than defending champion Iga Swiatek had taken to claim the first set in her 6-0 6-1 win against Sweden's Rebecca Peterson.
The match boiled over when Gauff, tiring of the type of delaying tactics from world No.121 Siegemund, raged at chair umpire Marijana Veljovic.
The teenager could barely contain her delight when Veljovic deducted Siegemund a point for not being ready to receive, giving Gauff a 5-1 lead in the decider.
"Slow!" was Gauff's verdict on the match after setting up a second-round clash with 16-year-old Mirra Andreeva.
Siegemund, whose faults drew applause and whose own back-and-forth with Veljovic drew jeers, cried during her post-match news conference, saying the fans "had no respect for me."
"I am very, very disappointed (by) the way the people treated me today," she said.
There is no doubt that I'm slow. ... I should be quicker. But at the same time, it's how I play."
Added Siegemund: "They treated me like I was a bad person."
World No.1 Swiatek needed just 58 minutes to roar into the second round, getting her title defence off to the perfect start as she seeks a fifth grand slam title.
The 22-year-old from Poland dropped just eight points in the first set.
Sweden's Peterson did get on the board early in the second but Swiatek wrapped up the win in just 58 minutes.
The top seed will next face Australian Daria Saville after her equally impressive 6-0 6-2 thumping of American teenager Clervie Ngounoue.
There was an early upset on day one with eighth seed Maria Sakkari bowing out to Spanish world No.71 Rebeka Masarova.
The Greek complained after her 6-4 6-4 loss that she was bothered by the smell of marijuana.
Former world No.1 Caroline Wozniacki marked her return to grand slam action for the first time in more than three years with a 6-3 6-2 win over Russian qualifier Tatiana Prozorova.
Wozniacki is competing in her third tournament since returning to the tour after retiring in 2020 to start a family.
Czech Karolina Muchova was the first player into the second round after a 6-4 6-0 victory over Australia's Storm Hunter and two-time Australian Open champion Victoria Azarenka downed Fiona Ferro of France 6-1 6-2 for her 15th first-round win at Flushing Meadows.
Swiss 15th seed Belinda Bencic put out Kamilla Rahkimova from Russia 6-2 6-4 to advance, while 16th seed Veronika Kudermetova was beaten 7-5 6-4 by local Bernarda Pera.
Nineteenth-seeded Beatriz Haddad Maia of Brazil took out 2017 champion Sloane Stephens 6-2 5-7 6-4 and fourth-seeded Elena Rybakina, last year's Wimbledon champion, defeated Marta Kostyuk of Ukraine 6-2 6-1.
With AP & Reuters.