New York — When Tommy Paul was a kid growing up in Greenville, North Carolina, his family would drive the 500 or so miles up to New York the week before the U.S. Open to watch qualifying matches — "It was free," he notes — and catch a glimpse of some pros practicing.

A couple of times, according to Paul, those treks involved a visit to an emergency room on the tournament grounds: his sister was bitten by a poisonous spider; his mother passed out and hit her head after seeing a player get badly injured.

"Every year," Paul said, "we always had something terrible happen."

This trip to Flushing Meadows is going far more smoothly so far for Paul — and other American men. The 26-year-old Paul, the No. 14 seed, earned a debut appearance in the fourth round at the U.S. Open by hitting 15 aces and getting broken just once during a 6-1, 6-0, 3-6, 6-3 victory over No. 21 Alejandro Davidovich Fokina of Spain in Arthur Ashe Stadium on Friday.

"I was kind of, like, 'Really, they're putting me on Ashe?' I knew there was a pretty strong schedule of people," said Paul, who never before had played in the 23,000-seat main stadium. "I was kind of surprised. ... Hopefully I'll be back many more times."

That's bound to happen if he keeps playing like this. Paul is part of a group of 20-something American men making moves on tour, and at this hard-court tournament, against a backdrop of a 20-year drought since the last major tennis championship for a man from the United States.

"These guys are all such good friends. They grew up together. They've trained together. They've played on teams together. They know each other's games so well. And they see each other as equals in a lot of ways," U.S. Davis Cup captain Bob Bryan said. "And when one of that group is making a dent on the tour, it's only natural that the others start to believe, as well."

At least one American is guaranteed a spot in the quarterfinals, because Paul's next opponent is unseeded Ben Shelton, a 20-year-old from Florida. Shelton advanced Friday by defeating Aslan Karatsev of Russia 6-4, 3-6, 6-2, 6-0 with the help of 26 aces.

Also into the fourth round is No. 10 Frances Tiafoe, a 25-year-old from Maryland, who was a 4-6, 6-2, 6-3, 7-6 (6) winner against No. 22 Adrian Mannarino of France. Tiafoe reached his first Grand Slam semifinal at the U.S. Open a year ago — beating Rafael Nadal before losing to eventual champion Carlos Alcaraz — and is the first man from the United States to get to the fourth round in New York for four consecutive years since Andre Agassi in 2002-05.

Tiafoe was not exactly in fine form ahead of his return: He lost three of four matches on hard courts leading into this U.S. Open.

Not that he cares about that now.

"The summer's irrelevant," Tiafoe said. "It's all about this tournament, honestly."

Looking to join him and the other Americans: No. 9 Taylor Fritz, who was scheduled to meet Czech qualifier Jakub Mensik at Louis Armstrong Stadium on Friday night, and wild-card entry Michael Mmoh, who plays Saturday.

The Ashe schedule at night featured Coco Gauff vs. Elise Mertens, followed by 23-time major champion Novak Djokovic vs. Laslo Djere.

Earlier, defending women's champion Iga Swiatek raised her 6-0 set total this season to 19 by eliminating her good friend Kaja Juvan 6-0, 6-1 in 49 minutes with an edge of 21-2 — that's not a typo — in winners; 2018 Australian Open winner Caroline Wozniacki continued her comeback after 3 1/2 years in retirement by defeating Jennifer Brady 4-6, 6-3, 6-1; and French Open runner-up Karolina Muchova got past Taylor Townsend 7-6 (0), 6-3.

Entering the 2022 U.S. Open, Paul never had won a match at the place. Then he claimed a pair of five-setters before bowing out in the third round against runner-up Casper Ruud.

"Normally when I'm done with tournaments, I don't watch anymore," said Paul, who signed his initials on one fan's head Friday. "But 'Foe' is pretty much my favorite player to turn on and watch, so I couldn't not tune in and watch it. ... It not only brings confidence to him but also to us, because we all know that we can play at that level, too."

Sure enough, at the next major tournament, the Australian Open this January, Paul produced his own breakthrough by making it to the semifinals before losing to Djokovic. Paul defeated Shelton in the quarterfinals there; they teamed up in doubles at the Miami Open two months later.

"There is very healthy competition amongst all of us," Paul said about the U.S. contingent. "I mean, in no way would I say jealousy between us. We push each other with results or in practice."