World number two Roger Federer launches his bid for a sixth US Open title, and his first since 2008, with a first-round match against Argentina's Leonardo Mayer at the Arthur Ashe Stadium on Tuesday.
The 34-year-old Swiss has been in sparkling form this season and heads into the final grand slam event of 2015 buoyed by an impressive hardcourt run in Cincinnati earlier this month.
"Now I've got the confidence, I've got the matches and I'm actually still feeling really fresh even after this week," Federer said after beating world number one Novak Djokovic in the Cincinnati final eight days ago.
"Everybody knows it's your last chance to do well at a slam or win a slam," the 17-times grand slam singles champion said of the U.S. Open. "So there are not really easy matches out there. Just want to make sure I get going good at the very beginning."
Also in action at Flushing Meadows on Tuesday will be third-seeded Scot Andy Murray and fifth seed Stanislas Wawrinka of Switzerland.
Murray faces controversial Australian Nick Kyrgios, who hit the headlines earlier this month when he insulted opponent Wawrinka during a match in Montreal, saying that Thanasi Kokkinakis had slept with the Swiss player's girlfriend.
Wawrinka, meanwhile, will launch his own US Open title bid with a first-round match against Spaniard Albert Ramos-Vinolas.
In the US Open women's championship, big-serving Czech Petra Kvitova, the fifth seed, takes on Germany's Laura Siegemund and second-seeded Romanian Simona Halep comes up against Marina Erakovic of New Zealand.