American Ben Shelton booked a ticket to his first US Open final with a four-set win over compatriot Frances Tiafoe.
And (briefly), the 23-year old shattered a grand slam record along the way.
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Early in the third set of the all-American semi-final encounter, Shelton sent down a thundering serve that drew gasps from the crowd, with Tiafoe only able to parry it over the net for a simple winner.
There was further amazement as the courtside speed gun clocked the serve at 158 miles per hour – roughly 254 km/h.
But amid the excitement, Shelton’s sceptical reaction was quickly mirrored around the tennis world.
“Ben’s looking at the gun going “I don’t think that’s right”,” commentator Jim Courier said.
“That might be a mistake by the gun, because if it is, I’ve got to believe that’s the fastest US Open serve ever.
“I think Sam Groth went faster at a Challenger.”
The previous grand slam record was set by Frenchman Giovanni Mpetshi Perricard at the 2025 Wimbledon Championships, clocked at 244 km/h.
However, the US Open would soon confirm that on closer inspection, the speed gun had malfunctioned, with the serve reduced to a still impressively fast 232 km/h.
However, correct or not, Shelton’s serve comfortably fell short of Australian Sam Groth’s all time record of 263.4 km/h, set in 2012.
The drama came as an inspired Shelton ousted the popular Tiafoe 4-6, 6-3, 6-3, 7-5 to reach his first grand slam final.
The eighth seed, who ousted reigning champion Carlos Alcaraz in an epic five-set quarter-final, landed 85 per cent of his first serves and hit a whopping 20 aces to prove too powerful for his compatriot.
“He’s like a big brother to me,” Shelton said of Tiafoe.
“This is both of our favourite tournament in the world, our favourite court in the world.
“To be able to light it up in front of you guys is the best feeling that there is.”
The American has the chance to end a 23-year Grand Slam singles title drought for US men dating back to Andy Roddick’s 2003 US Open victory by defeating Zverev.
Shelton, whose father Bryan is African-American, has also become the first man of colour to reach the decider at Flushing Meadow since 1972 – the legendary Arthur Ashe, for whom the main court at the US Open is named.
He will face top seed Alexander Zverev in the decider, who out-duelled Russian Karen Khachanov 6-3, 7-6 (9/7), 7-6 (8/6) on Friday to reach his third straight Grand Slam final.
Zverev, who followed up his maiden major at the French Open with a runner-up finish at Wimbledon, saved two set points in the final tiebreaker to close it out in straight sets.
“Sometimes things go your way. I feel like I’ve had a little struggle at the major level,” Zverev said.
“I was so close so many times and maybe this year God has said this is going to be your year and enjoy your time on the court.
“I’m enjoying it and playing these big finals. I can’t wait for Sunday.
“It’s going to be incredibly special. Frances and Ben are the crowd favourites here in New York. Everybody loves them.
“Hopefully I cannot make the American dream come true on Sunday.”
Top-ranked Zverev also reached the US Open final in 2020, where he lost in five sets to Dominic Thiem.
Khachanov, ranked 50th, failed to reach his first Grand Slam final. The 30-year-old Russian fell to 3-7 against Zverev, who also beat him in the Tokyo Olympic final.
Khachanov swatted forehands beyond the baseline to surrender a break in the eighth game and then drop the first set as Zverev held serve in the ninth.
Zverev broke again to open the second set, Khachanov sending a backhand long after failing to land a first serve in the game, but later Zverev double-faulted to hand the Russian a break for 2-2 as they fought into a tie-breaker.
Khachanov smacked a backhand down-the-line winner to reach 7-7 in the breaker but Zverev captured the second set two points later when the Russian hit a forehand wide.
In the third set, both men held all the way into the tie-breaker. Zverev saved two set points when Khachanov sent forehands wide and long.
Zverev followed with his final ace and won when the Russian sent a forehand long after two hours and 58 minutes.
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“After the second round I was sitting with my team in the locker room and laughing our asses off at how bad I’ve been playing,” he said.
“That sense of humour helped me. The next day on the practice court I’ve been feeling the ball a lot better. Moving forward I was playing much better tennis.
“Obviously I was playing much better tennis or I would not be in the US Open final.”
Sky Sports Tennis’ Martina Navratilova said: “What a year Zverev has had at the majors. It’s been outstanding stuff.
“Okay, Sinner lost early at the French Open and Alcaraz didn’t play, but there are no asterisks, he still had to get through even as a favourite.
“And that has given the confidence to play better tennis after that.
“I think he played better at Wimbledon than he did at Roland Garros, and now he started off badly here by his own admission, but he hasn’t lost a set the last four matches.
“He’s cooking now.”