NEW YORK — Carlos Alcaraz used his youth, athleticism and creativity to assert himself against the much more accomplished — but also much older — Novak Djokovic and beat the 24-time major champion 6-4, 7-6 (4), 6-2 at the U.S. Open on Friday for a berth in his third consecutive Grand Slam final.

By the end, Djokovic was “gassed out,” as he described it afterward, and seemed resigned to the result. The 38-year-old from Serbia reached the semifinals at all four Slams this season but exited in that round each time, three via losses to No. 2 Alcaraz, 22, or No. 1 Jannik Sinner, 24.

“It’s frustrating on the court when you are not able to keep up with that level physically, but at the same time, it’s something also expected, I guess,” Djokovic said. “It comes with time and with age.”

Alcaraz hasn’t dropped a set as he pursues his sixth major title and second at Flushing Meadows. He defeated Sinner at the French Open in June and lost to his rival at Wimbledon in July.

Go back to April, and Alcaraz is 44-2, making it to the final at each of his last eight tour-level events.

“It’s something that I’m working on, just the consistency on the matches, on the tournaments, on the year, in general. Just not having up-and-downs in (a) match,” Alcaraz said. “Probably, I’m just getting mature, just getting to know myself much better, what I need on, off the court.”

Alcaraz had lost his two most recent matches against Djokovic: in the gold-medal final at the Paris Olympics last year, and in the Australian Open quarterfinals this January.

“It’s not easy playing against him, to be honest,” Alcaraz said. “I’m thinking about the legend, what he has achieved in his career. It’s difficult not to think about it.”

Djokovic’s bid to become the first player in the sport’s history to get Slam No. 25 was blocked again, and he thinks part of the issue is trying to overcome much younger men in best-of-five set matches.

“I still want to play … (a) full Grand Slam season next year,” Djokovic said. “Let’s see whether that’s going to happen or not, but … Slams are Slams. They are just different from any other tournament. They are the pillars of our sport, the most important tournaments we have. But I do fancy my chances a bit more in best-of-three.”

Djokovic’s shots were not quite on-target early and, but for a brief interlude in the second set, his usual verve was not present. He rolled his eyes after one miss, grimaced after another. At changeovers, he flexed or stretched his neck, which bothered him earlier in the tournament, and also was looked at by a trainer.

There also was the occasional bit of brilliance, including a two-handed backhand passing shot that drew raucous roars from the crowd, which often cried out his nickname, “No-le!” and seemed to want to will him to at least make things more competitive, if not win.

Djokovic even managed to steal one of Alcaraz’s service games while taking a 3-0 lead in the second set. Might this portend a long, tight match?

Nope. Alcaraz immediately snapped to, taking the next three games, including one scooped cross-court forehand passing winner that was so superb even Djokovic felt compelled to applaud with his racket.

Alcaraz never faced another break point.