Rafael Nadal exults after winning the first set against Matteo Berrettini. Nadal will face Daniil Medvedev in Sunday’s men’s singles final. (Eduardo Munoz Alvarez/AP)

A U.S. Open that fumbled two of the renowned Big Three in its first nine days somehow wound up with a sparkler of a final anyway. Second-ranked Rafael Nadal will play No. 5 Daniil Medvedev, and anybody counting the fait as accompli before Sunday at 4 p.m. is guilty of excessive napping.

Certainly, Nadal would be every bit as favored as his upper arms, with his 2019 season blossoming from an early night of wreckage. At ages 32 and then 33 starting in June, he has reached the Australian Open final (where Novak Djokovic destroyed him), the French Open title podium, a Wimbledon semifinal and the U.S. Open final as of Friday night’s 7-6 (8-6), 6-4, 6-1 breakdown of Italian revelation Matteo Berrettini.

Speaking of revelations, the Djokovic-lessness and the Roger Federer-lessness of it all didn’t leave Nadal opposite somebody scarily overmatched. It left him playing Medvedev, the 6-foot-6 definition of lankiness, whose 7-6 (7-5), 6-4, 6-3 win over longtime Bulgarian stalwart Grigor Dimitrov exhibited Medvedev’s will and pluck.

Nobody reaches 20-2 in a summertime hard-court season in North America without will and pluck, but there Medvedev stands. He has beaten 12 top-40 players, three top-10 players and the players ranked first (Djokovic) and fourth (Dominic Thiem) in a run through Washington (to the final), Montreal (to the final), Cincinnati (to the title) and Flushing Meadows, to his first Grand Slam final in his first passage beyond a fourth round. He will find an opponent playing in his fifth U.S. Open and 27th Grand Slam final, seeking titles No. 4 and 19 in those abundant categories, yet he will find one who said, as did Nadal, “He’s the player that is playing better today on tour during the summer.”

By “better,” in his charming second language, Nadal seemed to mean “best,” and he said of Medvedev, “He’s making steps forward every single week,” those steps including the Montreal final where Nadal schooled Medvedev, 6-3, 6-0, another backdrop here.

“He just fights right,” Dimitrov said of Medvedev. “That’s it. He puts every ball in the court. Somehow he gets to the balls. Doesn’t give you enough free points. I think that’s the major thing that I see right now.”

Medvedev’s capacity for escapes that seem almost illusory turned up against Dimitrov in a first set in which everyone seemed to agree the Bulgarian who ousted Federer played better than the Russian who had pounded through Stanislas Wawrinka in the quarterfinals. In seeking clues as to why Medvedev won a set in which he got two fewer points, you might look at confidence. “The confidence means a lot in this case,” Medvedev said, “because I do think he was better player in the first set. I do think I was kind of lucky to win it. Then the momentum changed completely.”

He also said, “We had some amazing level, I think.”

They had some amazing level, all thought, but then Medvedev proved superior even in the first semifinal of a 23-year-old. And in that way tennis undresses a person and reveals some inner moxie, he apparently has that, too, having sparred a bit with New York fans along his six-match path to this pinnacle.

“It’s funny because actually when I was like, I don’t remember, 6 or 7 [in Moscow], I liked wrestling because I thought it’s for real,” he said. “My parents were like: ‘Why are you watching this? This is just a show.’ I was like, ‘No, they’re fighting for real.’ But I don’t think it has any — how you say? — impact on what’s been happening here. As I said before, I want to be a better person than I was a few days here.”

His coach, Frenchman Gilles Cervara, said he requires a different, subtle kind of coaching and called Medvedev both “smart” and, after rummaging around for the English word, “subtle.” That’s right: A so-called villain who gave a subtle finger to a third-round crowd comes off as a guy unusually personable and nice. “Yeah, I will not say that I’m a kind person or a good person,” he said generously. “I can only say that I’m a really calm person in life. I actually have no idea why the demons go out when I play tennis.”

Demons are coming Sunday in Nadal’s shots, which slowly wore down Berrettini, who proved far more impressive than perhaps anticipated. That first-set tiebreaker saw him arrange a 4-0 lead and two set points at 6-4 before he lost them against the all-time fighter, including an ill-advised drop shot that wobbled into the net.

Berrettini, like Medvedev in a first Grand Slam semifinal at 23, also walked a rope for a good, long while, saving the first nine break points Nadal had against him. Finally, a 10th came through another dying-quail drop shot, and when a low Berrettini attempt went low into the net, Nadal pumped those fists. The match would show the stresses of the Italian’s task in that he served for 117 points, while Nadal just 75. Break-point rates: Nadal 4 for 16, Berrettini 0 for 0.

Such numbers do cause inconvenience, especially against Nadal.