How the rivalry between Jannik Sinner and Carlos Alcaraz dominated tennis in 2025

Jannik Sinner draped his left arm and his racket around Carlos Alcaraz's neck. Alcaraz then put his right arm on Sinner's shoulder.

The friendly greeting between the two players after the latest in a series of high-stakes matches was a fitting image for the year in men’s tennis.

Sinner and Alcaraz are dominating the game and their levels are so close that they keep alternating who wins the biggest titles.

Alcaraz beat Sinner in a fifth-set tiebreaker in the French Open final; Sinner got revenge at Wimbledon; Alcaraz won again at the US Open; and then Sinner defended his ATP Finals title before his home fans in Turin on Sunday.

Alcaraz sealed the year-ending No. 1 ranking, while No. 2 Sinner goes into the offseason coming off a confidence-boosting victory over his rival.

"The facts are they're a level above everyone," said Felix Auger-Aliassime, who was beaten by both Sinner (in the group stage) and Alcaraz (in the semifinals) at the season-ending event for the top eight players.

"The ranking doesn't lie. They're the two best players. That's the facts. Different game styles, but both put extreme pressure on their opponent in different ways," added Auger-Aliassime, who ends the year at a career-high No. 5. "They keep showing up and playing good, so credit to them."

Added ATP chairman Andrea Gaudenzi, "These two guys are really incredible for our sport, both on and off the court."

It was the most-watched tennis match in Italian TV history with 7 million viewers, according to numbers released by the national ratings service Monday. Sinner, who also won the Australian Open, reached the final of all four Grand Slams and the finals — despite missing three months near the start of the year after settling a doping case. Like in 2024, Sinner didn't drop a set at finals—becoming the first player in the event's history to achieve that feat in two different years.

"I feel to be a better player than last year," Sinner said. "All the losses I had, I tried to see the positive thing and trying to evolve me as a player. I felt like this happened in a very good way."

Alcaraz acknowledged a year ago when he won only one match during the group stage at finals that he still had to learn how to play indoors.

Well, consider him adept at the surface now.

"I didn't doubt about playing and fighting toe-to-toe with Jannik on indoor court," Alcaraz said. "I'm pretty sure that it's going to keep growing up, my level on indoor court."

After the loss to Alcaraz at the US Open, Sinner said he wanted to improve his serve and the results were evident in Turin where he dropped his serve only once—in the opening game of the second set against Alcaraz.

"He's actually pumped up the miles per hour and he is getting the ball closer to the line, which means he gets a lot more free points," Darren Cahill, one of Sinner's coaches, said of the Italian's first serve.

There was also a big 187 kph (116 mph) second serve from Sinner that helped him save a set point against Alcaraz late in the second set.

"I had already served two or three second serves in the same way (in that game) and I kept on losing the point. So I had to come up with something different. I decided for the riskiest option," Sinner said. "Sometimes you need a bit of courage and some luck. I would rather lose that point then have him win it."

Added Alcaraz, "That surprised me."

Auger-Aliassime also reached the US Open semifinals in September, and his ranking rocketed up from No. 30 midway through the year.

"I've always believed, since I'm a kid believed, and my ambition was to win Grand Slams and be No. 1 in the world," the Canadian said. "Now it's a matter of doing the right things to improve. If I do, we'll see where that leaves me."

At 25, Auger-Aliassime is older than both Sinner (24) and Alcaraz (22).

"We want (Sinner) to be playing his best tennis when he's 28, 29, 30 years of age," Cahill said. "Hopefully we're setting the plan and platform for him to be able to do that in a few years."

While Alcaraz was heading to Bologna to represent Spain in the Davis Cup finals this week, Sinner was starting his offseason and already focusing on 2026. Sinner will be the two-time defending champion at the Australian Open and then will attempt to win the French Open for the first time.

"Clay is going to be a big target for us next year," Cahill said. "We'll keep working on that."