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.

He 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.

The 23-year-old 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.

“I’m really happy, I don’t what know to say,” said Berrettini, who 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.

“Right now I don’t remember any points, just the match point.

“I remember also the double fault (on match point at 5-3). I have to be honest what a great fight. I would like to say congrats to Gael.

“I think when I was playing it was one of the best matches I ever saw. I was playing but I was watching also.”