Taylor Fritz became the first American man in 15 years to reach a Grand Slam singles final as he beat compatriot Frances Tiafoe in a five-set US Open thriller.
Fritz fought back to beat his good friend Tiafoe 4-6 7-5 4-6 6-4 6-1 under the lights in New York.
Andy Roddick was the last American man to win a major singles title, having triumphed at the US Open in 2003.
Roddick was also the last American man to reach a Grand Slam singles final - at Wimbledon in 2009 - as well as being the last to reach a US Open final in 2006.
Fritz will face world number one Jannik Sinner in Sunday's final at Flushing Meadows.
The 12th seed had previously never made it beyond the quarter-finals of a Grand Slam in four attempts.
"He overwhelmed me at the start and I was freaking out a little," Fritz, 26, said.
"I did all I could to stay in it. If I hadn't done that, I'd regret it forever."
It is a second semi-final loss in two years for Tiafoe, who was beaten by eventual champion Carlos Alcaraz at the same stage in 2022.
There could also be an American champion in the women's singles final when Jessica Pegula takes on Belarus' Aryna Sabalenka on Saturday.
Fritz enjoyed a positive start in front of a packed house on Arthur Ashe, breaking Tiafoe at the first opportunity to race into a 3-0 lead.
But Tiafoe, one of the sport's most engaging players, readjusted, winning six of the following seven games to wrap up the first set.
Fritz was much more competitive in the second set, dropping just one point on serve before breaking Tiafoe as he attempted to force a tie-break.
However, any momentum was soon ripped away from Fritz.
Tiafoe broke in the opening game of the third and his powerful serve, combined with some impressive athleticism, saw him take a two-sets-to-one lead.
However, the pressure told. Serving at 4-5, Tiafoe double faulted twice to slip from 40-15 to deuce, before two wild errors gifted the set to Fritz.
Tiafoe struggled to regain his intensity, with Fritz charging into a 4-0 lead before his opponent, willed on by the crowd, regained a break.
However, it was not enough, with Tiafoe immediately going 0-40 down on serve to be broken straight back, and Fritz confidently served out the win.