Unlike his arch rival Roger Federer, Rafael Nadal is into the Flushing Final Four.

Nadal advanced to his eighth U.S. Open semifinal after repelling gritty Argentine Diego Schwartzman 6-4, 7-5, 6-2 past midnight at Arthur Ashe Stadium.

“Here I am semifinals, it’s super important for me,’’ said Nadal, who was treated for cramping in his forearm. “It means everything.”

Schwartzman, with countryman Manu Ginobili on hand, gave the fans a show by rallying from 4-0 down in the first set to tie it at 4-4. In the second set, the 5-foot-7 jitterbug came back from two breaks down at 5-1 to put the match on serve and forge a 5-5 tie.

Schwartzman pulled off a handful of spectacular retrievals, rousing the crowd into a frenzy by putting his hand to his ear. The Argentinian fight song “Olé’’ rose up late in the second set.

But the No. 20 seed couldn’t pull out either stanza. Nadal is two wins away from his 19th Grand Slam title — which would be one away from Federer’s record. The Spanish Bull also is vying for his fourth Open title, which would move him one shy of Federer’s five.

There was buzz Nadal and Federer finally would meet in the final for the first time at the Open. It’s one of the craziest aspects of their 40-match rivalry, having never sparred on Flushing soil.

On paper, Nadal looks to have an easier path, facing in Friday’s semifinals surprising No. 24 seed, Rome’s Matteo Berrettini, who became the first Italian man to make the Open semifinals in 42 years.

“He’s hitting huge and making great strides every week,’’ Nadal said, about Berrettini.

The 23-year-old rising prospect flopped on his back after capitalizing on a fifth match point and pulling out a day-card fifth-set tiebreaker against Gaels Monfils.

“I was dreaming this since I was a child,’’ Berrettini said. “I was tired and I felt to just leave myself on the court.”