By having fun and pushing each other, the U.S. men brought the energy to the US Open

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Coco Gauff’s doubts—and, more importantly, her reaction to them—proved to be an apt description of the mood of the entire fleet of American players in Flushing Meadows. The U.S. men and women made this one of the most enjoyable of tournaments for the domestic audience, and one of the most profitable to them. The numbers:

The U.S. placed 24 women and 17 men in the singles draws. Granted, the wild-card system tends to load up Grand Slam main draws with host-nation hopefuls (11 Americans, including Venus Williams, earned wild cards). But the tally of 41 is still a very good number. Nine men and 11 women won their opening matches. Five of those men reached the third round, as did seven women. Those are the players we’ll look at here.

For Part One of this series featuring the U.S. women, click here.

Part Two, The Men

As a lucky loser earlier this year, injury-plagued Michael Mmoh won two main-draw matches at the Australian Open, including an upset of No. 12 seed Alexander Zverev. At this US Open, he eliminated John Isner in the American stalwart’s career-concluding, second-round appearance (fittingly, it was decided by a fifth set tiebreak). Mmoh, was then beaten by British up-and-comer, 21-year-old Jack Draper.

“He [Mmoh] was just there having fun,” Mmoh’s father Tony, a former ATP pro, told the ATP media team following the win over Isner, “That's what I want to see him do more, just have fun. I think when you relax a little bit more, you can start playing great tennis.”

Among the Americans, Tommy Paul is second only to Ben Shelton as a rapidly improving talent. True, it has taken the 26-year old longer to hit his stride, but his increased dedication and determination—along with his fluid, multi-purpose game—have put him on the cusp of the Top 10. (He is currently No. 13.) Paul showed his new mettle in an impressive second-round, five-set battle against heavy-hitting Roman Safiullin.

Although he was beaten by compatriot Shelton in the fourth round, Paul was thrilled with the progress of the American men.

“Yeah, it's pretty cool,” he said after his comeback from two sets down against Safiullin. “When I was on the court it, like, showed it up on the big screen, like Americans remaining in the tournament. It was pretty cool to see that."

Taylor Fritz, the No. 9 seed, is a core member and leading cheerleader for the cohort of hard-charging U.S. men. He even bridled at one point when he was asked about being “friendly” with his confreres.

“I probably shouldn't say that I'm ‘friendly’ with them,” he replied. “ They are, like, my closest friends. If one of us does something, the others not only want to do it too, they now believe that they can.”

Fritz won nine consecutive blow-out sets to find himself in the quarterfinals, up against the eventual champ, No. 2 seed Novak Djokovic. Unfortunately, Fritz’s first-serve then deserted him. “It's not rocket science,” he said after he was beaten in straight sets. “ I'm not going to be able to beat him [Djokovic] or hang with him when he just gets to return second serves.”

Frances Tiafoe did a good job of handling the pressure that came along with his newfound status as the co-darling (with Coco Gauff) of the Big Apple. The charismatic 25-year old, the latest American to crack the ATP's Top 10, looked ahead to his quarterfinal with Shelton with confidence.

“Ben has wanted to play me at the Open for a long time,” Tiafoe said, sounding very elder statesman-ish. “So he's going to be super excited. He's going to come out with a lot of energy. I'm just going to have to tame him down, try to be the vet and get the win.”

Shelton’s blazing serve and massive forehand proved too much for Tiafoe, though, over the course of a four-set exhibition of explosive power tennis by both men.

“American tennis is in a great spot, probably the best spot in a really long time,” Tiafoe had said earlier. Shelton provided the proof in the pudding.

Ben Shelton emerged as one of the brightest young stars of the ATP, as well as the big gun of American men’s tennis at this tournament.

Tiafoe, his close friend put it best before their match when he said, only somewhat metaphorically: “He's just an extremely loud player. Hits the ball big, serves huge, pretty much serving at 150 mph. Throwing his whole harm at that thing. He's so pumped up. Comes to the net. He's got great volleys. He's really athletic.”

Although Djokovic was too consistent and too long on match-management experience in their semifinal, Shelton proved a quick study. After he was blitzed in the first two sets, his free swinging and abundance of power enabled him to push Djokovic hard in set three before the Serbian star closed Shelton out in a tiebreak.