In the first set of the US Open semifinal, he claimed a 55 shot point to end the first set and he held on for a victory that put him in his second grand slam title match of the year.
The spectators booed when he was called "Ruuuuud!'' and it sounded like they were booing instead of saluting.
The runner-up at the French Open is a young man from Norway who could move to the top of the rankings if he wins the US Open.
"AfterRoland Garros, I was, of course, extremely happy, but also humble enough to think that could be my last one,'' he said.
He is back at that point a few months later. His opponent in the final will be either Carlos Alcaraz of Spain or a US based player. If Alcaraz wins the tournament, he will have a chance to take over the top spot from Medvedev. If Alcaraz loses in the semifinals, it will end the US Open at the top of the rankings.
In New York, all four men's semifinalists made their first appearance. That was the first edition of the U.S. Championships and it had not been done in over a century.
The game plan worked for most of the day against the 31st-ranked Khachanov, a 6-foot-8 Russian with a powerful serve who eliminated Wimbledon runner-up Nick Kyrgios in five sets in the quarterfinals
The effect of Khachanov's serves would be mitigated by the fact that he was behind the baseline. Deep groundstrokes that could finish off points were delivered by Ruud, who was flawless for side-to-side defense.
He came up with an over-the-shoulder volley winner that put him ahead 6-3 in the tiebreak. The point of the match was on the third opportunity to end the set. It took 75 seconds and contained 19 more strokes than the second-longest rally of the entire two weeks.
His father was smiling. The kid put his fingers on his hand. His name could be next to his name one day.
He was encouraged by the way he played at the end of the set, despite the fact that he hated to lose it.
He said that he was pumped in a way that we had a long rally. It was a pain to lose a set with this point. I was on the other side and I wanted to keep going.
In the second set, he broke to go up 2-1. After Khachanov surged late in the third to make things a bit more interesting, Ruud broke to lead 2-1 in the fourth, ripping a down-the-line forehand winner from the doubles alley.
This is the latest step in the evolution of the player. 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.
What have you done since then? He has a 13-2 record at the majors.
The AP contributed to the story.