INDIAN WELLS, Calif. — With no teenagers and no Daniil Medvedev left in the draw, this tournament will definitely not be a repeat of the U.S. Open.

Medvedev, so cool and pressure-proof on his way to his first Grand Slam title last month in New York, looked ready to keep rolling on Wednesday at the BNP Paribas Open.

He led Grigor Dimitrov by a set and two breaks of serve in the round of 16. But tennis remains an unpredictable game, and the top-seeded Medvedev proceeded to lose his way in the desert sunshine as Dimitrov, playing patiently and boldly at just the right times, reeled off wins in eight straight games and then held firm to finish off the upset, 4-6, 6-4, 6-3.

“Impossible until possible, I guess,” Dimitrov said in a television interview.

But if this is not the U.S. Open, it is not truly the Indian Wells tournament, either. That event, usually held annually in March, has grown in size and stature under its free-spending owner, Larry Ellison, becoming the most popular and prestigious tour stop after the four Grand Slam tournaments and the year-end tour finals.

In 2019, 475,000 spectators came to the Indian Wells Tennis Garden during the event’s nearly two-week run, filling up the stadium courts and the upscale restaurants that overlook them. In recent years, the tournament generated an estimated annual economic impact of over $400 million in the greater Palm Springs region.

But in March 2020, it became the first major international sports event to be canceled because of the coronavirus pandemic. The decision, which was ultimately Ellison’s call, turned out to be the correct one. Though there were skeptics when the move was announced just ahead of the qualifying tournament, other leagues and events soon followed as the scope and threat of the pandemic became clearer.

“We thought they were nuts at first for calling it off,” Krystal Meier, a longtime fan and tournament attendee from Long Beach, said in an interview last week. “How could anybody have known what was coming?”

This year, the BNP Paribas Open was moved from March to October, and though the prize money is roughly the same as in 2019, the star power and atmosphere are not.

According to tournament officials, attendance is on track to be about half of what it was in 2019. The change in date is certainly a factor. Many seasonal residents have yet to arrive in the area, and regulars who made March attendance a tradition were clearly not ready to embrace October.

The decision to require vaccination of all spectators may have limited the overall numbers while reassuring some fans. “When we saw everybody was going to be vaccinated, we definitely felt better about coming,” Meier said.

But there is still underlying concern about attending mass events and traveling too far from home. More than 87 percent of the spectators in 2019 were from outside the Palm Springs area.

Another reason for the smaller crowds is surely the changing of the guard in tennis. The tournament is missing the two biggest stars in the women’s game (Serena Williams and Naomi Osaka) and the three biggest stars in the men’s game (Roger Federer, Rafael Nadal and Novak Djokovic).

Federer, 40, and Nadal, 35, are recovering from injuries, and they announced the end of their 2020 seasons in August. Djokovic, 34, is resting and recovering after losing to Medvedev in straight sets in last month’s U.S. Open final, a defeat that stopped him just short of becoming the first man to complete a Grand Slam in singles since Rod Laver in 1969.

Dominic Thiem, who won the men’s title here in 2019, is also out with an injury. He, like the other high-profile absentees, still has a presence in Indian Wells. In a nod to the obvious, tournament organizers have put life-size images of all of them on a wall behind Stadium 2 featuring the words “We miss you.” It has become a magnet during the event, with fans posing for photographs next to the photographs.

Posing next to flesh-and-blood players has been much trickier because of the pandemic restrictions, which have meant a ban on official autograph sessions. (Informal signings have still taken place.)

None of the women’s singles quarterfinalists in New York reached the quarterfinals here, with the surprise Open champion Emma Raducanu losing in her opening match to the 100th-ranked Aliaksandra Sasnovich.

The far more experienced Medvedev fared better with his bedeviling blend of offense and defense, and he fared very well against Dimitrov until he took a 4-1 lead in the second set.

But Dimitrov, the Bulgarian who is seeded No. 23, was opportunistic enough to change the momentum. At 30, he has yet to reach the heights that have seemed his destiny, given his stylish, all-court game. But he remains a dangerous opponent, and after showing flashes of fine form at the San Diego Open the week before Indian Wells, he lifted his game on Wednesday as Medvedev’s dropped.

“He definitely flipped the switch,” Medvedev said. “It’s not that I started missing everything and like really playing bad. I still maintained some level, if we can call it like this. In so many matches, it would be enough to finish the match.”

Once in the rallies, Dimitrov almost exclusively sliced his single-handed backhand down the stretch and waited — and waited — to take big risks with his forehand. Most of them paid off in the final set, and he took a 5-1 lead as Medvedev expressed displeasure in rare fashion by breaking a racket between his first and second serves (he double faulted) and going on to lose his serve for the sixth time.

“That shows how slow this court is, and the conditions are more like clay, I would say, which I don’t like,” Medvedev said.

Dimitrov soon lost his serve, too, as he tried to finish off the upset at 5-1, but he did not falter at 5-3, holding at love and thrusting both arms into the air.

Though the sky above him was typical Indian Wells — clear and azure — what was happening back on earth remained anything but business as usual.