(Photo credit: Geoff Burke-Imagn Images)

The U.S. Open got off to a promising start for the two biggest hopes in American men's tennis.

No. 4 seed Taylor Fritz defeated countryman and wild card Emilio Nava 7-5, 6-2, 6-3, while No. 6 seed Ben Shelton cruised past Peruvian wild card Ignacio Buse 6-3, 6-2, 6-4 on Sunday in New York.

This U.S. Open at Flushing Meadows is the 22nd anniversary of the last time an American man won one of the sport's four major tournaments, when Andy Roddick captured his only Grand Slam in 2003.

Fritz and Shelton have come close to ending that drought -- especially Fritz, who advanced to the final as the No. 12 seed last year before falling to World No. 1 Jannik Sinner of Italy.

On Sunday, Fritz hit 11 aces, won 78 percent of his first-service points (39 of 50) and saved all four break points he faced in a one-hour, 58-minute affair.

'I had a game where I had some good chances in the first set and I just missed a couple of returns, just didn't play as well as I could have in that moment,' Fritz said afterward. 'Against someone like Emilio with such a big serve, that might be the only chance I get.

'I was lucky to get another chance to break at the end of the first set and I think once I found that break, the return started working for me a bit more, loosened up and I did a good job holding my serve the whole match.'

Shelton -- a semifinalist at the 2023 U.S. Open and this year's Australian Open -- went 5-for-5 in saving break points while also winning 78.2 percent of his first-serve points (43 of 55). He brushed off 32 unforced errors and tried not to look too far ahead during his post-match interview.

'I think that as soon as you start looking ahead of yourself, you stumble over your own feet,' the ATP 1000 titlist in Toronto said. 'So for me, it's one match at a time, one day at a time and just grateful to be out here.

'I'm happy to come back here every year. This is the one for sure. This is the pinnacle of tennis for me, what I dreamed about when I was a kid.'

The first upset of the men's singles draw came when Frenchman Adrian Mannarino dismissed Dutch 29th seed Tallon Griekspoor 7-5, 6-4, 6-0. Both players hit 14 aces, but Mannarino had just three double faults while Griekspoor committed 10 among his 45 unforced errors.

Czech 16th seed Jakub Mensik defeated Chile's Nicolas Jarry 7-6 (5), 6-3, 6-4, while Spanish 18th seed Alejandro Davidovich Fokina needed just one hour and 26 minutes to eliminate Kazakhstan's Alexander Shevchenko 6-1, 6-1, 6-2.

Others to win their first-round matches included Eliot Spizzirri, Frenchmen Arthur Rinderknech and Ugo Blanchet, Italy's Luciano Darderi (No. 32 seed) and Tomas Machac (No. 21 seed) of the Czech Republic.

--Field Level Media