NEW YORK — Novak Djokovic covered his face with a towel, but he couldn’t hide his sobs from his courtside chair in Arthur Ashe Stadium. As he desperately tried to conceal his eyes from sight, he inadvertently exposed more of his face and his emotions were on full display for all to see.

Just one win away from reaching tennis immortality, he had instead finally shown himself to be mortal after all. Djokovic, 34, had no answers on Saturday for 25-year-old Daniil Medvedev and his blistering serve in the US Open final, as he was handed a stunning 6-4, 6-4, 6-4 loss.

It wasn’t the way he had dreamed about the day.

Saturday was supposed to be his coronation as the “Greatest of All Time,” the day he joined Rod Laver as the only men in the history of the Open era to achieve the elusive Grand Slam, and the tournament in which he surpassed his rivals Roger Federer and Rafael Nadal for most major titles by a male player at 21. He knew how high the stakes were and had said on Friday he was going to play the match as if it were his last.

But he had failed in his mission, and it wasn’t just disappointment he was feeling in the initial moments after the match.

“Relief,” Djokovic told reporters soon after about his primary emotion. “I was glad it was over because the buildup for this tournament and everything that mentally, emotionally I had to deal with throughout the tournament in the last couple of weeks was just a lot. It was a lot to handle.

“I was just glad that finally the run is over. At the same time I felt sadness, disappointment, and also gratitude for the crowd and for that special moment that they’ve created for me on the court.”

The scene at Ashe was everything Djokovic could have wanted. There was a crowd that consisted of the A-list of the A-list — Brad Pitt, Leonardo DiCaprio, Bradley Cooper, Spike Lee and Laver himself — and 24,000 others who wanted to witness tennis history. They chanted, “Novak, Novak, Novak” throughout the match, no matter the score, and waved Serbian flags and signs professing accolades and love. For Djokovic, who has always received mixed sentiments from crowds, the stage was set for the defining moment of his career.

But Medvedev was simply too prepared, too ready for the moment. Playing in his third major final, and having lost to Djokovic in the Australian Open final in February, he was determined to utilize a different strategy on Saturday, and he wasted no time implementing it.

Medvedev won 20 of his first 23 service points — and never eased up. He had 16 aces and nabbed an astonishing 42 of 52 points (81%) on his first serve. Djokovic was unable to solve the riddle.

“He was hitting his spots very well,” Djokovic said. “He came out very determined on the court. You could feel that he was just at highest of his abilities in every shot. He had a lot of clarity what he needs to do tactically. He has executed it perfectly.

“The other hand, I was just below par with my game. My legs were not there. I was trying, I did my best. Yeah, I made a lot of unforced errors. I didn’t have — no serve really. If you’re playing someone like Medvedev, who hits his spots so well, just aces, gets a lot of free points on his first serve, you’re constantly feeling pressure on your service games.”

With each ace or one of Medvedev’s 38 winners that whizzed by, Djokovic’s cheeks puffed out in frustration. He had a chance to break Medvedev, serving at 1-2 in the second set, but was first interrupted by inadvertent music (later identified as part of the “In memoriam” segment that aired on the video screen during a break) being played over the loudspeaker and the point was replayed. By the time he eventually lost the game, his anger had nearly bubbled over. He smashed his racket on the ground. Moments earlier he had appeared to restrain himself from tossing his racket.

Medvedev rattled off the next two games and dramatically shifted the momentum, leaving Djokovic few chances to reverse his fortunes.

He made a valiant effort after losing the first four games of the third set, and the crowd did its part to will him back into the match with loud cheers and chants, but it was simply too late and not enough.

It was all over in an astounding 2 hours and 15 minutes. Djokovic’s perfect record at majors this season, which looked so untouchable just eight weeks ago, was over. For those who had been paying attention since his victory at Wimbledon, it might not have been a complete surprise, but it still was a shocking conclusion to one of the best seasons in recent tennis history.

After Djokovic won his third major title of the year at the All England Club in July, the conversation quickly turned to his ability to achieve the “Golden Slam” in Tokyo. Steffi Graf had been the only player in history to do it in 1988, and Djokovic, having appeared invincible in the biggest matches of the years, seemed a near lock to win gold. The US Open seemed like a mere formality.

But the Olympic Games didn’t go to plan either.

Despite being up a set and a break, Djokovic lost to Alexander Zverev in the semifinals, thus ending his chance to join Graf in the record books. The next day, it got even worse. Playing Pablo Carreno Busta in the bronze-medal match, he couldn’t control his temper and threw a racket into the stands, and slammed another on the ground. He lost the match, then withdrew from the mixed doubles bronze-medal match moments later and left Tokyo empty-handed. He didn’t play again until New York.

Still, despite the hiccup and the monthlong break from competition, he was the overwhelming favorite to win in New York. When it comes to majors, there’s dominance, and then there’s Djokovic. With his Wimbledon win, he had taken 19 of the past 41 Grand Slam tournaments he had entered. With Federer and Nadal both absent due to injuries, a title seemed all but certain.

While young players like Medvedev and Zverev were considered threats, few believed they could defeat Djokovic in a best-of-five-set match or with so much on the line. Djokovic said achieving the calendar Slam would be the greatest achievement of his career at the tournament’s start and said he was “hugely inspired and motivated by that.” But he was quick to point out that he had to stay in the present and take it one match at a time. Following his win in the quarterfinals, he stopped ESPN’s Patrick McEnroe from asking about it because he later said he didn’t want to burden himself with it.

On the court, Djokovic’s play was nowhere near flawless, and at moments, he appeared vulnerable. He needed four sets in his first-round match against 18-year-old Holger Rune. He won just one match in straight sets, in the second round. In the semifinals, he needed a decider to defeat Zverev.

With just one win standing between him and the milestone, he quoted Kobe Bryant and said the job wasn’t yet finished. He talked about seeing Serena Williams come so close to the calendar Slam in 2015, before losing in the semifinals at the US Open, and how emotional she was after the loss.

He understood her pain even more on Saturday, and showed it.

Djokovic didn’t achieve what he had set out to accomplish on Saturday. But he did finally get something he had always wanted: adoration and genuine love from the tennis world. As the crowd showered him with an ovation after he won his fourth straight game in the final set, he raised his fist and smiled during the break. Through sniffles, he later told the crowd exactly what the support had meant to him during his on-court interview ahead of the trophy presentation.

“I would like to say that tonight even though I have not won the match, my heart is filled with joy and I am the happiest man alive because you guys made me feel very special in the court,” he said. “You guys touched my soul. I’ve never felt like this in New York, honestly. I love you guys.”

Often criticized for his polarizing off-the-court actions and opinions, and perceived as arrogant by others, Djokovic has simply never had the fanatical fandom experienced by Federer and Nadal. But this loss might have changed things. It wasn’t the calendar-year Grand Slam or a record-breaking major title, but Djokovic felt something positive in defeat.

“The emotion, the energy was so strong,” Djokovic said in his postmatch news conference. “I mean, it’s as strong as winning 21 Grand Slams. That’s how I felt, honestly. I felt very, very special.”