Matteo Berrettini became the first Italian man to reach the US Open semi-finals in 42 years Wednesday to set up a potential showdown with title favorite Rafael Nadal, who resumes his quest for a 19th Grand Slam crown.
Berrettini, the 24th seed, matched Corrado Barazzutti's run to the last four in 1977 after outlasting 13th-seeded Frenchman Gael Monfils 3-6, 6-3, 6-2, 3-6, 7-6 (7/5) in three hours and 57 minutes.
The 23-year-old from Rome will meet the winner of a later match between Spanish three-time US Open champion Nadal and Argentina's Diego Schwartzman for a place in Sunday's final at Flushing Meadows.
Berrettini joined Barazzutti, 1976 Roland Garros champion Adriano Panatta and Marco Cecchinato as just the fourth Italian to advance to a men's Grand Slam semi-final in singles.
"What a great fight. I think it was one of the best matches I maybe ever saw -- I was playing but I also saw. I'm really happy I don't know what to say," Berrettini said.
The first-time Slam quarter-finalist blew a 5-2 lead in the final set and four match points before finally seeing off Monfils in a thriller at Arthur Ashe Stadium.
"I was lucky I had match points and he didn't have it -- it's better when you have them. I'm really proud of myself, I was always focusing on the next point."
A nervous Berrettini doubled-faulted on his first match point at 5-3 before a resolute Monfils fought off two more on his serve to send the deciding set into a tie-break.
Monfils coughed up a costly pair of double faults in the breaker -- and 17 in total -- as Berrettini surged 5-2 ahead, the Frenchman rescuing a fourth match point before a booming serve from the Italian clinched a memorable win.
"Right now I don't remember any points, just the match point. I remember also my double fault I must be honest," Berrettini said.
- 'Tough' pill to swallow -
Defeat for Monfils prolonged France's lengthy wait for a first men's Grand Slam title since Yannick Noah won the French Open in 1983.
"I know how to bounce back, I've had some tough ones here before," said Monfils, who was beaten by Roger Federer in the 2014 quarter-finals after holding two match points.
"It was tough, I was just competing as much as I could but there was a big lack of serving today."
"I'm going to take the positive from these two weeks," he added.
Second seed Nadal -- the winner at Flushing Meadows in 2010, 2013 and 2017 -- plays Schwartzman in the night session at Arthur Ashe Stadium and is the unquestionable favourite as the only former champion left in the men's field.
The Spaniard is the only member of the "Big Three" still standing in New York after Federer followed Novak Djokovic through the exit door after a five-set loss to Grigor Dimitrov.
Nadal has defeated Schwartzman in all seven prior meetings but the 20th seed from Argentina can take heart from 78th-ranked Dimitrov's upset of Federer, the Bulgarian having faced a similar predicament before dumping out the Swiss star in Tuesday's quarter-final.
Schwartzman eliminated sixth seed Alexander Zverev in the last 16 to match his deepest Slam run. At 5ft 7in (1.70m) he would be the shortest Grand Slam semi-finalist since 5-foot-6 Harold Solomon at Roland Garros in 1980.
"He is playing amazing, nothing new, he's one of the players with the best talent on tour," Nadal said of Schwartzman, who also made the last eight in New York in 2017. "It will be a big challenge. I have to play my best. I'm happy for him. He's a close friend and I hope to play a great match."