Jannik Sinner failed to defend his US Open title in 2025, losing out to his greatest rival in the final.

Coming up short in four sets, Sinner was beaten by Carlos Alcaraz, 2-6, 6-3, 1-6, 4-6, on Arthur Ashe Stadium.

The Italian gave it his all but was no match for the Spaniard, who produced one of the most clinical serving performances of his career to secure the title.

Carlos Alcaraz lifts the US Open titlePhoto by CHARLY TRIBALLEAU/AFP via Getty Images

Sinner has now lost seven of his last eight matches against Alcaraz, as he continues to struggle against the world number one.

Many are concerned about the one-sided nature of their rivalry, although one former WTA star noticed something positive in Sinner during the final.

Caroline Garcia says Jannik Sinner was ‘mentally still there’ even when heading to defeat in the US Open final

Appearing as a guest on the Roland Garros podcast, Caroline Garcia was commenting on what makes Sinner so great when she highlighted what he did during the latter stages of the US Open final that impressed her.

“The speed of his ball, the way he hits the ball, and it looks like he’s taking time away from the opponent in the way he’s able to not miss even though he hits the ball so hard. He moves very well, but when he arrives to the ball, he’s able to hit it hard, not just push it in,” she said.

“Very good serve, great returner, maybe for now, compared to Alcaraz, he’s a bit less comfortable at the net, I think he will be able to do it, but he’s quite talented and a hard worker, so I have full confidence in him. At the beginning, he was not a great server, but now he’s worked on it and he’s one of the best. 

“Mentally, he’s always there, in the fourth he was down 5-1, or 5-2, he was looking at his box, encouraging himself like I can do it, positive, you felt like nothing could happen to [Carlos] Alcaraz, but the guy mentally was there, and it looks like he’s committed to improving his game.”

Jannik Sinner celebrates during his defeat to Carlos Alcaraz at the 2025 US OpenPhoto by Elsa/Getty Images

On the flip side, Garcia shared what she thinks makes Alcaraz so special.

“In my opinion, it’s because he is so complete; he can do everything, and he can do everything very well,” she said.

“At the beginning, when he arrived, his serve was not as good, but in the last year he has improved it a lot with his speed and his accuracy, against Sinner he served very well, every time he was in danger he was able to get an ace or a short ball and a winner in two shots, which was not always the case before.

“He can do everything; he can hit the ball very hard from the back of the court, he can use some more effect and volume in his shot, at the net he is good, has great hands, the best drop shot on tour right now, moves very well.

“The final against Sinner was very impressive; it was not as spectacular as Roland Garros, but the guy was just so much better.”

It’s Alcaraz who has the edge in their rivalry, although Garcia believes the Spaniard needs Sinner more than Sinner needs Alcaraz…

Carlos Alcaraz ‘really needs’ Jannik Sinner – Caroline Garcia

The Frenchwoman explained why the world number one needs Sinner to play his best tennis.

“Obviously, Jannik and Carlos are above all the other players for now,” she said.

“But they…Carlos definitely needs Sinner; he started to play really good this year when Jannik came back. 

“It looks like the mentality of Jannik is a bit different, but Carlos needs competition; he needs a rival, and when he has one, he’s very good, and his focus is way better and more consistent.

Jannik Sinner and Carlos Alcaraz shake hands after the US Open final.Photo by MANDEL NGAN/AFP via Getty Images

“He really needs a rivalry, and obviously, he knows how to do everything, but he needs someone in front of him to be able to challenge him and push him further.”

Alcaraz may be in luck, as it doesn’t look like Sinner will be going anywhere anytime soon.

The likelihood is that we will see Alcaraz and Sinner continue to dominate on the ATP Tour over the next few years.