NEW YORK — Extra excitement hovered over the US Open before Friday night’s historic semifinal at Arthur Ashe Stadium.

Thousands of fans — some dressed in star-spangled sweaters, shirts and hats — filed in at Flushing Meadows, pledging their allegiances to Frances Tiafoe or Taylor Fritz ahead of the Open’s first semifinal match between two American men in nearly two decades.

And while only one could win — as Fritz did, in five sets — the most marquee match of this year’s tournament in Queens served as a symbol of the rise of U.S. men’s tennis.

No. 12 Fritz defeated No. 20 Tiafoe — 4-6, 7-5, 4-6, 6-4, 6-1 — in a three-hour, 18-minute match to advance to Sunday’s men’s singles final, where Fritz will face top-seeded Jannik Sinner.

“It’s the reason why I do what I do,” an emotional Fritz said in his on-court interview. “It’s the reason why I work so hard.”

Fritz is the first American to reach the men’s final since Andy Roddick in 2006. With a win Sunday, Fritz would become the first American man to claim the Open crown since Roddick in 2003.

“It’s a dream come true,” said Fritz, who advanced to his first Grand Slam final.

Friday’s match lived up to the sky-high hype, with Fritz and Tiafoe trading points, sets and long volleys until Tiafoe faltered down the stretch.

After winning the first and third sets, Tiafoe dropped the final two, struggling to land his first serve in bounds.

He committed costly back-to-back double faults in the 10th and final game of the fourth set, allowing Fritz to break his serve.

Fritz then broke all three of Tiafoe’s serves in the fifth set, the second of which ended with another Tiafoe double fault.

Tiafoe landed only 39% of his first serves in bounds in the fourth set and 44% in the fifth.

The fault-filled finish occurred hours after Tiafoe won the first set despite dropping the first three games. He locked in to record four aces, win 80% of the points on his first serve and tally 11 winners in that opening set, all of which bested Fritz.

The second set was even tighter. Neither player won two consecutive games or broke the other’s serve until the end, when Fritz broke Tiafoe in the 12th game. Fritz won 93% of the points on his first serve, 100% on his second and delivered 15 winners to Tiafoe’s nine.

Tiafoe jumped out to a 2-0 lead in the third set and remained ahead even as Fritz applied pressure. That set’s final game ended with Fritz committing four consecutive unforced errors.

But in the end, Fritz played the more complete game, recording 42 winners to Tiafoe’s 38; 35 unforced errors to Tiafoe’s 50; and three double faults to Tiafoe’s nine.

Both earned cheers with every triumph, but a capacity crowd featuring Gayle King, Justin Theroux and Rory McIlroy leaned toward the charismatic Tiafoe over the lower-key Fritz.

For years, America’s top tennis tournament was dominated on the men’s side by international stars. Roger Federer, Rafael Nadal and Novak Djokovic combined for 13 titles from 2004-23, but with those three no longer simultaneously dominating, the U.S. continues to gain ground.

The ATP currently ranks five Americans within the top 20.

“There’s a window,” Tiafoe said earlier in the tournament. “There’s an opening in the game. … We had three greats playing at the same time and winning events. … I think this is definitely one that we can win. We just haven’t done it yet.”

And fans have noticed.

Tickets to Friday night’s all-American semifinal — the Open’s first since Andre Agassi beat Robby Ginepri in 2005 — started at $200 on StubHub.

Fans fortunate enough to snag a seat debated which American they would root for, listing factors such as whose playing style they preferred, who had the best chance to beat Sinner, or even which of the semifinalists they considered the most handsome.

“I’m rooting for Fritz. I really like him,” said Amanda Barone, 21, of Staten Island, noting she likes the way he plays. “But I like Tiafoe. I’m rooting for America!”

One attendee wore a Team USA jersey from the 1994 World Cup. Others balanced style with patriotism in flag-themed sweaters.

“All of these men who came up over the past few years on the American side, I think they’ve just reinvigorated the sport,” said Beth Pinsker, 35, of the Upper West Side, who wore an American-flag tank top and a red bandana.

“It’s been really incredible to watch [Federer, Nadal and Djokovic] dominate for so long, but it’s even more fun now to see it kind of turn over. And if it’s going to turn over, go USA.”

Friday marked Fritz’s first appearance in a Grand Slam semifinal. Tiafoe previously made it to the Open semifinal in 2022.

Fritz’s run at this Open included a quarterfinal upset of fourth-seeded Alexander Zverev of Germany, while Tiafoe beat fellow U.S. star Ben Shelton in the third round and ninth-seeded Grigor Dimitrov of Bulgaria in the quarterfinal.

The bond between the Maryland-born Tiafoe and Fritz, who hails from Southern California, dates back more than a decade to when they were competing in 14-and-under tournaments.

Fritz entered Friday’s match with a 6-1 record against Tiafoe, including wins at the Australian Open in 2022 and Acapulco last year.

“Taylor and I had a conversation about being 1, 2 Americans for a very long time,” Tiafoe said this week. “I remember we were sitting on a plane some years ago, and he’s a pretty to-himself kind of dude, and he’s, like, ‘Bro, I think me and you are going to be 1, 2 Americans and leading the way.’ … He’s had that mindset and he’s pushed me a lot.”

Fritz now sets his sights on Sinner, the Italian phenom who defeated the U.K.’s Jack Draper in straight sets at Ashe in Friday’s other semifinal match.

Sinner, 23, was permitted to compete at the Open despite testing positive for trace amounts of a banned steroid in March.

He avoided suspension after the International Tennis Integrity Agency accepted his claim that his physiotherapist used an over-the-counter spray containing the substance for a cut on his own finger, then gave Sinner a massage without gloves.

Sinner seeks his second Grand Slam title after winning the Australian Open in January.

Saturday’s women’s final, meanwhile, features Buffalo-born Jessica Pegula against Belarus’ Aryna Sabalenka.

Should Fritz and Pegula both win, it would mark the first time the U.S. claimed both Open singles championships since 2002, when Serena Williams and Pete Sampras achieved the feat.

©2024 New York Daily News. Visit at nydailynews.com. Distributed by Tribune Content Agency, LLC.