This was the third grand slam tournament in a row where these elite, young rivals met to decide the champion.
The match's start was delayed for about a half-hour while thousands of fans were stuck outside Arthur Ashe Stadium while going through extra security because President Donald Trump sat in a sponsor's suite. Perhaps the extra wait got to the No.1-seeded Sinner, who was the defending champion.
Right from the beginning, under a closed roof because of rain earlier in the day, Alcaraz outplayed the 24-year-old Italian, reversing the result from when they played for Wimbledon's title less than two months ago.
"I'm seeing you more than my family," Alcaraz joked, eliciting a grin from Sinner.
"It's great to share the court, to share the locker rooms, everything."
Alcaraz's leads over Sinner are now 10-5 in their head-to-head series, 6-4 in major trophies, and 2-1 in US Open championships. Plus, this two-hour, 42-minute win allowed Alcaraz, the 22-year-old from Spain, to take away the No.1 ranking from Sinner.
Sunday's showdown represented the first time in tennis history that the same two men played each other in three consecutive slam finals within a single season.
"You were better than me," Sinner told Alcaraz.
"I tried my best today. I couldn't do more."
Truth is, these two guys are so, so much better than the rest at the moment.
They have combined to collect the past eight slam trophies, and 10 of 13. Novak Djokovic, whom Alcaraz eliminated on Friday, took the other three in that span.
Alcaraz, who ended up with twice as many winners, 42-21, was superb in the first, third and fourth sets; Sinner's top efforts arrived in the second.
Since the start of the 2024 US Open, Sinner had won 33 of 34 matches at the majors; Sunday was his fifth straight final at those events. The loss? To Alcaraz at Roland Garros.
Indeed, over the last two seasons, Sinner is now 1-7 against Alcaraz — and 109-4 against everyone else.
Alcaraz, meanwhile, has won 37 of 38 contests since May. The loss? To Sinner at the All England Club, Alcaraz's lone defeat in a grand slam final.
In 2025, Alcaraz now has more titles (a tour-leading seven) than losses (his record is 61-6, also the best in men's tennis).
Sinner had dropped just one service game in his three matches leading into the decider, but Alcaraz broke right away and five times in all.
An 80 minutes in, it was a set apiece, after Alcaraz ceded one for the first time all tournament, allowing Australian Neale Fraser to retain his distinction as the most recent man to win every set he played at the event — in 1960.
As Sinner worked his way into things, he would celebrate points by pumping a fist towards the box where his coaches and others, including Olympic champion ski racer Lindsey Vonn, were seated.
But it was Alcaraz who seemed to have more ticket-buyers on his side.
They regaled him with standing ovations. For one particularly magical volley at a hard-to-believe angle struck just before the ball hit the court — even Alcaraz himself liked that one, saying "Wow!" and breaking into a wide grin.
