Carlos Alcaraz launches the defence of his US Open crown in New York on Tuesday, a day after Novak Djokovic produced a dazzling display to ensure he will replace the Spaniard as world No 1.
Alcaraz, who defeated Djokovic in a five-set Wimbledon final classic last month, opens his campaign with a night match against lowly ranked German Dominik Koepfer.
The 20-year-old Spanish star is aiming to become the first man to defend the US Open crown since 2008, when Roger Federer lifted the title for a fifth consecutive year.
Alcaraz went into this year's tournament as world No 1, but will lose that ranking after the event following Djokovic's imperious performance on Arthur Ashe Stadium on Monday.
The 23-time Grand Slam singles champion produced a near-flawless late night masterclass, routing France's Alexandre Muller 6-0, 6-2, 6-3 in a lop-sided victory.
It marked a successful return to New York for Djokovic, who missed the 2022 US Open after refusing to get vaccinated against Covid-19.
"I think the performance explains how I felt tonight, particularly in the first two sets. It was kind of lights-out tennis really, almost flawless, perfect first set," said Djokovic.
"Hopefully I can maintain that level. It's just the beginning of the tournament, but I already like the level of tennis."
In other men's draw games on Tuesday, 2021 champion and No 3 seed Daniil Medvedev kicks off proceedings on the main Arthur Ashe arena against Hungary's Attila Balazs.
Elsewhere, Britain's Andy Murray faces France's Corentin Moutet in his opening game, 11 years on from his lone US Open triumph in 2012, while Italian sixth seed Jannik Sinner takes on Germany's Yannick Hanfmann.
'TOUGH LOSSES'
In the women's draw, second seed Aryna Sabalenka of Belarus opens against Belgium's Maryna Zanevska.
Sabalenka, who opened 2023 by winning her first Grand Slam title at the Australian Open, has a good recent record at the US Open, reaching the semifinals in 2021 and 2022.
The 25-year-old from Minsk says she has become mentally tougher after her previous defeats in the tournament.
"Winning tough matches, losing tough matches," Sabalenka said. "What I learned in the past, all these matches, you're not losing them, you're learning to become stronger.
"I know that in the future these tough losses will help me to win some great matches."
Tunisia's Ons Jabeur is also making her entrance in the women's draw, desperately hoping she can finally break her Grand Slam duck after defeats in three finals in 2022 and 2023.
Jabeur, runner-up at Wimbledon and the US Open last year, suffered another agonising near-miss last month when she lost in the final at Wimbledon for the second year running.
The 29-year-old took a month off after her latest Wimbledon heartache, reaching the quarterfinals at the Cincinnati Open.
"They say time heals. I'm still waiting a bit," Jabeur said on the eve of the US Open. "The Wimbledon loss still hurts. It's much better than a month ago, for sure," added Jabeur, who faces Colombia's Camila Osorio in the first round.
