NEW YORK -- Rafael Nadal found himself trailing in a tight first set against a bigger, younger opponent who was finding ways to cause trouble in their U.S. Open semifinal.

Never one to panic, never liable to have a letdown, Nadal hung tough, waited for 24th-seeded Matteo Berrettini to wilt ever so slightly and then pounced.

Nadal moved closer to a fourth US Open championship and 19th Grand Slam title overall -- one away from Roger Federer's record for men -- by pulling away for a 7-6 (6), 6-4, 6-1 victory over Berrettini under the roof at Arthur Ashe Stadium on Friday night.

The second-seeded Nadal was down 4-0, then 5-2, then 6-4 in the opening tiebreaker before taking the next four points and was on his way.

"You don't want to be in a tiebreak against a player like Matteo. ... I was a little bit lucky, no?" Nadal said. "I survived at that moment and ... after that, the match completely changed."

Sure did. Nadal broke once in the second set and three times in the third, while never facing a single break point in the match.

He will face No. 5 seed Daniil Medvedev of Russia on Sunday.

It is Medvedev's first major final, Nadal's 27th. They've played each other once before, the final of the Montreal Masters hard-court tournament in August, and Nadal won 6-3, 6-0.

"He's one of the more solid players on tour," Nadal said. "He is making steps forward every single week."

Medvedev advanced earlier Friday by beating Grigor Dimitrov 7-6 (5), 6-4, 6-3 for his tour-leading 50th win of the season.

The 23-year-old Russian first made a name for himself at the U.S. Open by earning the wrath of spectators. During his on-court interview Friday, Medvedev referenced his "tournament of controversies," which included accumulating $19,000 in fines and antagonizing booing fans last week, saying he knew it was "not going to be easy with the public."

Medvedev's tennis was a bit scratchy Friday, and like Nadal, he barely avoided dropping the opening set. But he did just enough with his mostly defensive style to get past Dimitrov, who had eliminated Federer in a five-set quarterfinal.

"I do think he was better player in first set. I do think I was kind of lucky to win it," Medvedev said about Dimitrov. "Then the momentum changed completely. I think after, I was playing better than him in the next two sets."

A year ago at this time, Nadal was retiring from his semifinal against Juan Martin del Potro because of knee pain. He's famously had trouble with his body over the years, particularly when it comes to less-forgiving hard courts, but right now, he sure looks healthy, hale and hungry as ever.

The 33-year-old Spaniard -- Federer, it's worth noting just turned 38 -- made it to the semifinals at every major this year. Nadal lost in the Australian Open final to Novak Djokovic in January, won a 12th French Open title in June, and lost to Federer in the final four at Wimbledon in July.

Berrettini, 23, had never been to a Grand Slam semifinal but didn't look intimidated early on against Nadal.

A decade apart, this was their first matchup, and so the early stages were as much a chance for Nadal to familiarize himself with the guy as it was for fans who might not know much about Berrettini.

What's obvious is that his strengths are a big serve that tops 130 mph and a forehand that can end points. Less apparent at first glance is Berrettini's touch, which he showed off with about a half-dozen drop shots to claim points in the first set, taking advantage of just how faaaaar behind the baseline Nadal stood to return.

As the match progressed, Nadal started going more to Berrettini's backhand, avoiding that furious forehand. So Berrettini adjusted, too, running around his backhand as much as possible to get in position to swing away from his preferred side.

And swing away he did, throwing his barrel-chested, 6-foot-5, 198-pound frame behind forehands that repeatedly approached 100 mph. Nothing subtle about them. Berrettini is built like a boxer and he often borrows terms from that sport when discussing his matches, such as when he spoke metaphorically about wearing down opponent Gael Monfils with body blows in their exhausting five-set quarterfinal.

The key to the opening set and, indeed, the entire semifinal, was that tiebreaker.

Berrettini grabbed a 4-0 lead, then kept getting closer to the finish line. At 6-4, there he stood, needing one point to take the set, as raucous supporters stood and yelled -- including the fellow Roman who owns a restaurant on Manhattan's Lower East Side where Berrettini has been going for pasta throughout the tournament.

That, then, is when Nadal needed to dig in, and did.

Berrettini? Unaccustomed to these stakes and these moments, he wasn't quite up to the task.

Nadal flicked a forehand passing shot that dipped enough to make Berrettini's volley try rather tough, and the ball found the net. One set point erased. On the next, Berrettini tried a drop shot, but this one was only so-so and it, too, landed in the net. A second set point was gone, and Berrettini covered his mouth.

The next two points -- the last of the set -- also went to Nadal via errors by Berrettini, a backhand into the net on a 24-stroke exchange, followed by a forehand that sailed long. Nadal reacted by shouting and pumping his fist repeatedly. Berrettini's jaw dropped. Fans rose and roared.

Berrettini hardly packed it in from there, but Nadal was simply better, grinding away until his foe finally succumbed. After Berrettini managed to save nine break points in a row, Nadal converted his 10th of the match to lead 4-3 in the second set.

Once that set was his, Nadal broke to go up 1-0 in the third. And that, folks, was that.

Soon enough, Nadal was able to move on from this test and start thinking about beating Medvedev -- and gaining on Federer.

"It means a lot," Nadal said, "to be back where I am today."