Jannik Sinner is back on the hard courts of Cincinnati, eyeing another deep run at the Masters 1000 event where he’s the reigning champion. Today, he faces a familiar foe in Adrian Mannarino, a seasoned Frenchman who has just pulled off an impressive upset over Tommy Paul to reach the Round of 16. The stage is set at the P&G Center Court, where fans are bracing for a high-stakes showdown between two players with very different stories but equally strong ambitions.
Sinner’s journey to this point has been nothing short of dominant. The world number one hasn’t dropped a set in Cincinnati so far, dispatching both Daniel Galan and Gabriel Diallo with clinical efficiency. His form is a testament to the steady progress he’s made under the watchful eyes of his coaching team—despite rumors to the contrary, both Darren Cahill and Simone Vagnozzi are present in Cincinnati, supporting Sinner’s quest for back-to-back titles. As Cahill told ATPTour.com, "That’s why we are so proud as coaches, because all that work you’ve been doing for the past three years eventually shows up in a big match, at a big tournament, for him to be able to get through and win that match. So it’s not just four or five days when you can make those big changes. It’s the combination of a year or two of just pushing him day to day and making sure we continue to work on those things."
The improvements have been tangible. When Cahill began working with Sinner in 2022, the focus was on sharpening the Italian’s serve. Fast forward to 2025, and Sinner is not just the best returner on the ATP tour—he also boasts the third-best serve rating, trailing only Giovanni Mpetshi Perricard and Taylor Fritz. This evolution has made Sinner a formidable all-court threat and a favorite in every tournament he enters.
Mannarino, meanwhile, comes into this match riding a wave of confidence after defeating the No. 13 seed Tommy Paul in three sets—his first top-20 win since November 2024. Ranked No. 89 in the ATP standings, the 37-year-old Frenchman has proven he’s still capable of mixing it up with the sport’s elite, even as he enters the twilight of his career. His victory over Paul wasn’t without drama: electronic line calling errors marred the match, forcing a rare manual video review to decide a crucial point. Chair umpire Fergus Murphy told the crowd, "Ladies and gentlemen, as you can see, the video review shows that the ball is out. Game, first set: Paul." Mannarino, however, was less convinced, remarking, "We cannot see; no, we don’t even see the slow motion on the video." The incident underscored the growing pains of tennis’s transition to full electronic officiating—a theme that’s run through this year’s Cincinnati Open.
This isn’t the first time Sinner and Mannarino have crossed paths. In fact, their head-to-head history is decidedly one-sided: Sinner has triumphed in all three of their previous meetings. Their first clash came in the semifinals of the ATP 250 in Sofia in 2020, where Sinner won 6-3, 7-5. Two years later, at the Montreal Masters, the Italian came from behind to win 2-6, 6-4, 6-2. Their most recent encounter was at Indian Wells in 2023, with Sinner again emerging victorious. The numbers suggest Sinner has Mannarino’s number, but as this tournament has shown, upsets are never out of the question.
Sinner’s record in Cincinnati is also worth noting. Last year, he captured his first Masters 1000 title on these courts, defeating Frances Tiafoe 7-6, 6-2 in the final. His path to the trophy included wins over Alex Michelsen, Jordan Thompson, Andrey Rublev, and Alexander Zverev. Prior to his 2024 triumph, Sinner’s best result in Cincinnati was a Round of 16 appearance in 2022. In both 2021 and 2023, he exited in the Round of 32, losing to John Isner and Dusan Lajovic, respectively. Now, as the defending champion and world number one, he carries the weight of expectation—but also the confidence that comes with recent success.
Of course, the specter of Carlos Alcaraz looms large over any discussion of Sinner’s season. The two have developed one of tennis’s most compelling rivalries, trading blows on the sport’s biggest stages. In May, Alcaraz snapped Sinner’s 26-match win streak in the finals of the Internazionali BNL d’Italia, claiming his seventh ATP Masters 1000 title. The rivalry continued at Roland Garros, where Alcaraz battled back from two sets down to win the French Open final. But Sinner got his revenge at Wimbledon, defeating Alcaraz to claim his maiden title at the All England Club. Cahill summed up the dynamic succinctly: "We’re seeing an incredible level of tennis at the moment, with Carlos [Alcaraz] and Jannik. If you look at their body of work over the past couple of years, they’ve separated themselves from the field. Now it’s up to the field to chase." Whether the two will meet again in the latter stages of Cincinnati remains to be seen, but their rivalry is shaping the ATP landscape in 2025.
Beyond the on-court action, this year’s Cincinnati Open has served as a testing ground for tennis’s push toward full electronic line calling. The technology, designed to eliminate human error, has instead introduced new headaches. During Taylor Fritz’s first-round match against Brandon Nakashima, a clear out ball went uncalled, forcing an off-court official to intervene and replay the point. Fritz voiced his frustration, saying, "You’re in the chair and you saw the ball was like a foot out." The incident drew reactions from other players, with Daniil Medvedev commenting online, "Ball is out, point is over, point to Fritz." The ATP has responded by updating its officiating protocols: now, if the system fails and the ball is clearly out, the point will be awarded accordingly, even if play continues briefly. Still, the glitches have left players and fans questioning the wisdom of relying solely on automation, especially with all ATP tournaments set to adopt the technology in 2025.
So, as Sinner and Mannarino prepare to take the court, the stakes are high—not just for a place in the quarterfinals, but as a microcosm of the sport’s evolving landscape. Will Sinner’s consistency and firepower carry him through, or can Mannarino conjure another upset amid the uncertainty? And will the electronic officiating hold up under pressure, or will more controversy steal the spotlight?
The answers will unfold soon enough on the blue hard courts of Cincinnati, with the world watching and the future of tennis hanging in the balance. For now, all eyes are on Sinner and Mannarino as they battle for a coveted spot in the final eight.
