NEW YORK — Rafael Nadal’s 19th Grand Slam trophy went from inevitable to suddenly in doubt in a thrill-a-minute U.S. Open final.

What had all the makings of a casual crowning morphed into a grueling contest thanks to Nadal’s opponent, Daniil Medvedev, a man a decade younger and appearing in his first major title match. Down by two sets and a break, Medvedev shifted styles, upped his level against a rattled Nadal — and even received an unexpected boost from the Arthur Ashe Stadium spectators.

Truly tested for the only time in the tournament, the No. 2-seeded Nadal managed to stop Medvedev’s surge Sunday and hold off his historic comeback bid, pulling out a 7-5, 6-3, 5-7, 4-6, 6-4 victory in 4 hours, 50 minutes of highlight-worthy action and Broadway-worthy drama to collect his fourth championship at Flushing Meadows.

“One of the most emotional nights of my tennis career,” said Nadal, who covered his face with his hands while crying when arena video boards showed clips from each of his Slam triumphs.

“The last three hours of the match have been very, very intense, no?” Nadal said. “Very tough mentally and physically, too.”

Now at 19 majors — a total Medvedev called “outrageous” — Nadal is merely one away from rival Roger Federer’s record for men.

But this one did not come easily. Not at all.

Sure seemed it might, with Nadal ahead by two sets and a break in the third at 3-2, playing like “a beast out there,” as the No. 5-seeded Medvedev put it.

At that moment, Medvedev would joke afterward, this is where his thoughts were: “OK, in 20 minutes I have to give a speech. What do I say?”

But the 23-year-old from Russia did not go gently into the night. He broke right back to 3-all, then again to claim that set and yet again to end the fourth.

“The nerves were so high,” Nadal said. “A crazy match.”

Not since 1949 has anyone won a U.S. Open final after trailing by two sets to none. Never before had Medvedev won a five-set match. Only once before had Nadal lost a Grand Slam match after taking the opening two sets.

And yet the tension was real.

At the very end — or what appeared to be the very end — Nadal couldn’t close it out. After breaking to lead 3-2 in the fifth, in a game Medvedev led 40-love before flubbing an easy forehand, Nadal broke again and served for the championship at 5-2.

Andreescu tops Serena in women’s final

Bianca Andreescu knew this would happen, because she knows all about Serena Williams. Looked up to her. Dreamed of playing her.

Andreescu knew Williams would not go quietly. Knew Williams would not make things easy. And so as a big lead in the U.S. Open final dwindled Saturday, as she stuffed fingers in her ears to drown out the decibels from the delirious thousands filling Arthur Ashe Stadium, Andreescu knew she needed to be just as bold, and hit just as big, as she did earlier in the match — and as Williams has done for years.

Displaying the same brand of in-your-face tennis Williams seemed to invent, replete with strong serves, gutsy groundstrokes and “Come on!” cries, the 19-year-old Andreescu regained the upper hand and pulled out a 6-3, 7-5 victory at Flushing Meadows to win her first Grand Slam title and keep Williams from collecting a record-tying 24th.

This is the second year in a row that Williams has lost in the final at Flushing Meadows. This one had none of the controversy of 2018, when she got into an extended argument with the chair umpire while being beaten by Naomi Osaka.