Watching Daniil Medvedev speak is like watching a tornado from inside Dorothy’s farmhouse in “The Wizard of Oz.” His thoughts whirl at such a rapid clip that you do not even have time to run to a storm cellar.

Then it becomes clear: Medvedev, the world No. 2 and winner of this year’s United States Open, answers questions a little like he plays tennis — fast and furious, seemingly without stopping to take a breath.

“The most important thing is that I’m trying to be myself on the court,” he said on a video chat from Paris when told that his peers have described him as a chess master, a genius and an octopus. “I’m just trying to play good tennis and win matches. Then I let other people decide what they think.”

In September, Medvedev, 25, of Russia, served as the ultimate spoiler when he upset the world No. 1, Novak Djokovic, 6-4, 6-4, 6-4 to win his first major at the U.S. Open. Djokovic had already won the Australian and French Opens and Wimbledon in 2021, and a win at the U.S. Open would have made him just the sixth singles player, and third man, to capture the Grand Slam. Medvedev’s win also denied Djokovic a record-breaking 21st career major. Instead, he, Roger Federer and Rafael Nadal are still tied with 20 majors apiece.

“He has definitely improved a lot, and the Grand Slam win at the U.S. Open did not come as a surprise to me,” Djokovic said. “He has a tremendous serve, and he hits his spots in the box incredibly well. That’s the biggest weapon of his game, without a doubt.

“Then, of course, that backhand is very flat, and he’s just as strong as a wall from that side,” Djokovic added. “He just doesn’t miss. And he’s improved his forehand a lot. He’s very professional and very smart on the court. He’s game savvy. He understands how to use the court, how to position himself when he’s defending, when he’s attacking. His net game has improved as well, so he doesn’t hesitate to come forward. Nowadays he’s become a more all-around player, more complete and, as a result, he’s a Grand Slam champion.”

Medvedev is trying to defend his championship at the season-ending Nitto ATP Finals, which begins Sunday and has moved from London to Turin, Italy, this year. Last year, Medvedev beat Alexander Zverev, Djokovic, Diego Schwartzman, Nadal and Dominic Thiem to capture the title.

When Medvedev first ascended to No. 2 in March, it was, in large part, because he won his last 10 matches of 2020 and his first 10 of 2021. He was finally stopped by Djokovic in the Australian Open final in February.

“Daniil has perfected the game that he’s playing that not many players can play,” said the fourth-ranked Stefanos Tsitsipas, who has lost to Medvedev six of the eight times they have played. “I call him ‘octopus’ for a reason. He’s just able to get balls that not many people are able to.”

It is odd, then, that Medvedev constantly refers to his flagging self confidence.

“There was a moment when I was not confident in myself,” he said. “I was doubting a few things about my physical abilities, my tennis abilities. I was in doubt, which is what tennis is all about. Then I won these two amazing tournaments [2020 Rolex Paris Masters and Nitto ATP Finals], beat a lot of top players, got a boost of confidence where I was like, ‘OK, I believe in myself. There is no reason not to believe anymore.’”

Medvedev was never a prodigy. He was not ranked No. 1 in the juniors, never even went beyond the third round at any of the major junior tournaments. But that did not stop him from aspiring to play among the best.

“I was never even in the quarters of a slam,” Medvedev said. “But when you come to these Grand Slams, no matter if you’re ranked 30, 20 or I think I was 13 at the max, you see all these top players that you look at on TV and they actually do normal things. They eat, they take a shower, they go play matches, they can even laugh with you juniors. And you actually feel in a way that you belong with this group.”

Before Medvedev ever played tennis, he said he was known in the family for his temper tantrums around the house. His two older sisters, Julia and Elena, were powerless to control him.

“I remember when I was 4 years old, I was a little bit ‘wanty,’” Medvedev said with a chuckle. “Like if I wanted something I could start crying. I think that’s the part that could sometimes show on the tennis court, especially when I was younger, because the thing is, what do you want on the tennis court? You want to win.”

Medevedev has proved his petulance more than once in his pro career. In 2016, he was defaulted from a Challenger match in Savannah, Ga., for suggesting that the chair umpire was favoring his opponent based on race.

Then, during the 2019 U.S. Open, Medvedev was booed by the New York crowd during a match against Feliciano Lopez when he got a warning from the umpire for tossing his racket and then snatching a towel from a ball man. As the fans roared their disapproval, Medvedev tugged on his ear, imploring them to continue.

Then, during his post-match interview, Medvedev told the crowd: “Thank you all, guys, because your energy tonight gave me the win. If you were not here, guys, I would probably lose the match. So I want all of you to know, when you sleep tonight, I won because of you.”

The crowd responded by booing even louder. Medvedev won his next three matches before he was beaten by Nadal in the final.

Just before the start of the Paris Masters in October, Medvedev and Djokovic had a two-hour practice session at the Mouratoglou Academy on the French Riviera. It was the first time the two had seen each other since their U.S. Open final in September. They chatted for 15 minutes after the practice, but neither one mentioned their encounter in New York.

“It’s normal, no matter if you lose or win you don’t speak about these matches because there’s going to be one loser who’s not going to want to speak about it,” said Medvedev, who also lost to Djokovic last Sunday in the final of the Paris Masters. “And when I win I also don’t want to say, ‘Hey, remember …’”

When Medvedev was about 14, he said, he read the book “Eragon” by Christopher Paolini. He was so captivated by the fantastical story about magic, glory and power that he read all 528 pages in three nights, at the same time imagining he was part of that world.

Now that he is enmeshed in his own fantastical world, Medvedev refuses to revel in it.

“I don’t look back too much in my life,” he said. “I like to think about the present and the future more than the past, even if the past is good. I use it more as confidence, to say, ‘Wow, I managed to win, to beat Novak in the final of a slam.’ I’m going to use it more if I have doubt in my career, which can happen.

“If you lose first round or quarters of some tournaments, maybe two in a row, you’re always going to have questions, like ‘Am I going to be able to come back?’ That’s when you can look back at this match and say to yourself, ‘Wow, it’s possible.’”