Roberto Carballes Baena had seven aces while delivering a huge upset of fourth-seeded Holger Rune 6-3, 4-6, 6-3, 6-2 on Monday in the opening round of the U.S. Open at New York.

It marks the first time the 30-year-old Carballes Baena has beaten a Top 10 player in 14 career attempts.

Baena converted 7 of 14 break points and committed just 21 unforced errors to Rune’s 43. The Spaniard also converted 75.9 percent of his first-serve points.

Rune had a 37-31 edge in winners but said he wasn’t at his best. The Denmark native took a timeout during the third set to get treatment for a leg injury and is still bothered by a back ailment sustained earlier this month.

“Disappointing day today,” Rune said. “I had, as you know, a setback after the tournaments in Toronto and (Cincinnati), where I had to retire. Not the best preparation I had.

“Not satisfied with the result, obviously, but also with my tennis. There is only one way, and it’s to work.”

While crediting Carballes Baena, Rune also pointed to the physical issues as the reason for the defeat.

“I think also one of the reasons, you know, it’s not ideal that I didn’t get more matches coming into this tournament, because the body, it’s hard if you’re not in the rhythm for the body,” Rune said.

Carballes Baena, who has reached the second round in four straight U.S. Opens, will next play Aslan Karatsev of Russia in the second round. Karatsev was a 6-3, 6-3, 6-3 winner over Jiri Lehecka of the Czech Republic.

Fifth-seeded Casper Ruud, a finalist in last year’s U.S. Open, began his tournament with a 7-6 (5), 3-6, 6-4, 7-6 (5) victory over qualifier Emilio Nava. It was Ruud’s 200th tour-level victory.

Ruud made just 21 unforced errors while Nava had 49. The American had 72 winners — including 13 aces — while Ruud had 27 and four, respectively.

Ninth-seeded Taylor Fritz rolled to a 6-2, 6-1, 6-2 victory over Steve Johnson in a clash of Americans. No. 10 Frances Tiafoe advanced with a 6-2, 7-5, 6-1 victory over Learned Tien.

Former U.S. Open champion Dominic Thiem swept past No. 25 Alexander Bublik of Kazakhstan 6-3, 6-2, 6-4. Thiem was helped by Bublik’s 17 double faults.

The 2020 U.S. Open champ has been bothered by injuries over the past two-plus years. It was the Austrian’s first Grand Slam victory since the 2021 Australian Open. He had failed to win a single match in his last six Grand Slam appearances.

“It’s a pretty special victory because it’s the first since two-and-a-half years on Grand Slams,” Thiem said. “Especially here at the U.S. Open with all the past and all the memories I have here.”

No. 21 Alejandro Davidovich Fokina knocked off Marcos Giron 6-4, 6-4, 6-2, while No. 22 Adrian Mannarino of France registered a 7-5, 6-7 (3), 6-3, 7-5 victory over Japan’s Yosuke Watanuki.

No. 32 Laslo Djere of Serbia was a 7-5, 6-4, 6-4 over Brandon Nakashima.

Ben Shelton recorded a 1-6, 6-3, 6-2, 6-4 victory over Argentina’s Pedro Cachin. But fellow American J.J. Wolf went down as China’s Zhizhen Zhang outlasted him 7-5, 7-5, 6-7 (5), 4-6 and 6-3.

Other winners included Argentina’s Juan Manuel Cerundolo, Hungary’s Fabian Marozsan, Austria’s Sebastian Ofner, Czech Jakub Mensik and Australia’s Rinky Hijikata.

–Field Level Media

Novak Djokovic and Carlos Alcaraz have forged a new rivalry at the top of men’s tennis, and they could be headed for a third epic showdown this summer.

Entering the U.S. Open, Djokovic is coming off a dramatic win over Alcaraz at the Western & Southern Open earlier this month. That provided a measure of payback after the young Spaniard dethroned the all-time Grand Slam king in a five-set thriller at Wimbledon last month.

Alcaraz holds the No. 1 ranking entering the final Grand Slam of the year, and he’s the defending champion in Flushing Meadows, N.Y. However, it’s Djokovic who is the slight favorite to win the men’s title at +175 ahead of Alcaraz at +170 at BetMGM.

The Serbian, who is attempting to add on to his record 23 Grand Slam titles, leads the book with 35.2 percent of the total bets and 48.9 percent of the money wagered on the men’s champion backing him to win. Alcaraz is close behind with 27.9 percent of the tickets but has drawn just 19.4 percent of the money.

No other player has shorter than third-seeded Russian Daniil Medvedev’s +1000 odds, which has drawn modest public support with 5.8 and 5.5 percent of the action, respectively. No. 6 Jannik Sinner of Italy has been the third most popular player, having been backed by 8.35 percent of the bets and 5.8 percent of the money at +1400.

The odds are similar at DraftKings, where Djokovic is the +120 favorite, followed by Alcaraz (+190), Medvedev (+1100) and Sinner (+1400).

Djokovic will begin his quest for a 24th Grand Slam title against unseeded Alexandre Muller at 8:15 p.m. ET on Monday, while Alcaraz kicks off his title defense against unseeded Dominik Koepfer at the same time on Tuesday.

Alcaraz, 20, is attempting to become the first player to successfully defend a U.S. Open title since Roger Federer in 2008. His half of the draw includes Medvedev, Sinner and No. 8 seed Andrey Rublev of Russia.

“I feel that I’m more mature on court. I feel that I’m a better player than I was a year ago,” Alcaraz said in his pre-tournament press conference. “I got my first Grand Slam last year, but I feel like I’m more mature and I’m better.”

Djokovic, 36, faces a draw that includes Denmark’s Holger Rune, the No. 4 seed, and No. 5 Casper Ruud of Norway, along with No. 7 seed Stefanos Tsitsipas of Greece and the American trio of No. 9 Taylor Fritz, No. 10 Francis Tiafoe and No. 14 Tommy Paul.

After taking the first two Grand Slam titles of the year, Djokovic’s record in majors this year is 20-1 — with the lone blemish being the instant classic against Alcaraz at Wimbledon.

“Grand Slams are the biggest goals that I have in my career at the moment,” he said. “I always speak about that, that I aim to peak and perform my best in Grand Slams. I don’t know how many more Slams I’ll have. … I see every Grand Slam that I play right now as really a golden opportunity to make more history.

“Of course, there’s a big significance to that.”

–Field Level Media