Backed by chants of “Let's go Venus,” Williams broke to love and cut the deficit to 3-1. Any suggestion of a full recovery disappeared soon afterward when she dropped serve again, allowing Kenin to pull clear and close out the set 6-2.
The 2020 Australian Open champion then won three consecutive games to lead 3-1 in the second. Williams produced occasional reminders of the power and timing that helped her win seven Grand Slam singles titles, but those moments did not arrive often enough. Her second serve caused particular trouble, and unforced errors repeatedly interrupted promising stretches.
Kenin faced four break points while serving to level the set at 5-5. She saved all four, with Williams shouting in frustration after another series of mistakes handed her opponent the game.
Williams still held serve for 6-5, but Kenin answered to force a tiebreak.
Williams misses seven set points
Williams appeared to gain control during the tiebreak and earned seven set points, but she failed to convert any of them. Kenin stayed composed, survived the pressure and completed the straight-sets victory 8-6 in the breaker.
The timing remained a major issue for Williams afterward. Starting a first-round match around 1 or 2 in the morning, she argued, made it difficult for either player to find a rhythm or produce their best tennis.
“It's not ideal,” Williams said. “I would have preferred something else, definitely. It wasn't great for either of us, so I think we both tried our best.”
She also questioned why tennis allows matches to begin so late.
“I just don't know any other sport where you have to start that late. I definitely think there's room for improvement there.”
Williams added: “It's not easy to do in the first round. It's not easy to do it at 1 or 2 in the morning to try to find your rhythm and play your best, but I tried my best.”
Kenin will next meet Jessica Pegula, the highest-ranked American woman in the draw.
Medvedev and Pegula advance comfortably
Earlier, Daniil Medvedev avoided the first-round disorder that ended his run a year ago. The former US Open champion defeated French qualifier Hugo Gaston 6-4, 6-2, 6-4 at Arthur Ashe Stadium.
Medvedev arrived after early exits in Montreal and Cincinnati, results that raised questions about his form before the tournament. His opening performance was considerably less complicated.
“The last couple of weeks were not easy,” Medvedev said. “I'm happy that today I managed to produce high-level tennis.”
Pegula also progressed without much difficulty, beating Romania's Elena-Gabriela Ruse 6-3, 6-2 in the first match on Arthur Ashe. Dozens of ticket holders had queued well before play began, and the home crowd received a routine American victory rather than a prolonged overnight assignment.
Players are competing for a share of the tournament's record $108 million prize fund.
Krejcikova exits as Paolini survives
Barbora Krejcikova became the first seeded player eliminated from the tournament. The two-time Grand Slam champion saved six match points before losing 7-6(4), 6-2 to Kamilla Rakhimova on an outer court.
Jasmine Paolini faced a less terminal scare at Louis Armstrong Stadium. The Italian defeated Slovenia's Veronika Erjavec 6-3, 3-6, 6-4 and will play compatriot Lucrezia Stefanini in the next round.
Elsewhere in the opening round:
- Czech player Jiri Lehecka beat Spain's Pablo Carreno Busta 6-1, 7-6(5), 4-6, 6-2 on the Grandstand.
- Ukraine's Marta Kostyuk defeated Australia's Storm Hunter 6-4, 6-1 at the same venue.
- Elina Svitolina joined fellow Ukrainian Kostyuk in the next round with a 6-1, 6-2 win over Solana Sierra.
The tournament also lost two notable names shortly after play began. Former champion Marin Cilic and 2022 runner-up Casper Ruud withdrew because of injuries.
