NEW YORK -- Casper Ruud claimed a 55-shot point to end the first set of his US Open semifinal while building a big lead against Karen Khachanov and held on for a 7-6 (5), 6-2, 5-7, 6-2 victory Friday that put him in his second Grand Slam title match of the year.
When it ended, spectators in Arthur Ashe Stadium called out his name, "Ruuuuud!'' -- and it sounded sort of as if they were booing, rather than saluting.
Ruud, the runner-up to Rafael Nadal at the French Open in June, is a 23-year-old from Norway who can move from No. 7 to No. 1 in the rankings by winning the championship at Flushing Meadows on Sunday.
"After Roland Garros, I was, of course, extremely happy,'' Ruud said, "but also humble enough to think that could be my only final of my career.''
The winner of Sunday's final will unseat 2021 US Open champion Daniil Medvedev as the new men's world No. 1.
All four men's semifinalists were making their debuts in that round in New York. That had not happened at the event since 1881, when it absolutely had to: That was the inaugural edition of what was then known as the U.S. Championships.
Ruud is coached by his father, former professional player Christian, and the game plan worked perfectly for most of the day against the 31st-ranked Khachanov, a 6-foot-6 Russian with a powerful serve who eliminated Wimbledon runner-up Nick Kyrgios in five sets in the quarterfinals.
To mitigate the effect of Khachanov's serves, Ruud would stand way behind the baseline to return, then look to dominate exchanges from the baseline. Ruud used flawless footwork for side-to-side defense and found openings to deliver deep groundstrokes that could finish off points.
He came up with occasional brilliance, such as the over-the-shoulder volley winner that put him ahead 6-3 in the tiebreaker. Moments later came the point of the match, on Ruud's third opportunity to end that set. It lasted 75 seconds and contained 19 more strokes than the second-longest rally of these entire two weeks, culminating with a down-the-line backhand by Ruud that drew a netted forehand in response.
His dad smiled. His kid raised both arms and put up two fingers on his right hand. Could have been just the index finger to signify No. 1, which could be next to his name soon.
Khachanov couldn't recall a 55-shot rally in his career, and though he hated to lose it, he was initially encouraged afterward by the way he played at the end of the set.
"I felt pumped in a way that we had this long rally, we were moving both,'' he said. "I felt like, 'OK, it's a painful one to lose a set with this point.' On the other side I felt like, 'OK, now we're moving a lot, let's keep on going.'''
Ruud broke to go up 2-1 in the second set and was on his way there. After Khachanov surged late in the third to make things slightly more intriguing, Ruud broke to lead 2-1 in the fourth, ripping a down-the-line forehand winner from the doubles alley.
This marks the latest step in a real move forward for Ruud in Grand Slam play. He came into this year with a record of just 14-13 at the sport's most important events -- 3-4 in New York, where his best previous showing was a third-round appearance in 2020 -- then needed to sit out the Australian Open in January after twisting his ankle in practice the day before the tournament began.
Since then? He's 13-2 at the majors in 2022.
The Associated Press contributed to this story.