Darren Cahill says the work he and Simone Vagnozzi have done with Jannik Sinner focused on adding avenues to finish points, and that those changes helped convert a top-10 talent into a sustained world No 1. Cahill, who previously mentored Lleyton Hewitt and Andre Agassi, joined Sinner in July 2022, shortly after Vagnozzi began with the then rising player.

Under the two coaches Sinner has claimed two Australian Open titles, one US Open crown and the 2025 Wimbledon trophy. The 23-year-old has also spent the last 62 weeks at the top of the ATP Rankings and has been unmovable since becoming the first Italian world No 1 in June 2024.

On the coaching partnership Cahill was specific about roles and process. “I work hand-in-hand with Simone, he started about six months before I did, and he has been amazing. He had a vision for where Jannik’s game needed to go and we spent a lot of time together working through what technical changes he had to make,” he revealed.

Cahill described the technical priorities in detail. “Anything from a technical point of view, creating more ways for him to develop finishing skills, with his serve a little bit, his transition skills, all the stuff that all the great champions of the sport have in their arsenal.

“Jannik was already a great player, he was already a top-10 player, he hit the ball great from the back of the court, but he needed to work on more avenues to finish points.

“And so we went to work and we a really fortunate that we have a player who wants to get better every single day, he never settles for where he is at the moment, no matter what he achieves and every time he steps onto the court he is looking to improve as a tennis player.”

Cahill singled out the serve as a turning point. “One thing I did say is, ‘The serve needs to improve. You’re six foot four and you’re a strong lad’,” he revealed. “‘You need to be able to get more miles per hour on that first serve, better direction on that first serve.

“Then not only do you start winning some free points from your first serve, but also your Plus One becomes much more effective. If people can neutralise your serve, you have to work much harder for your points.

“Then his questions came, one after the other ‘How do I get better at the serve? What do I need to do?’ It’s typical of him. He wants to compete. He’s a competition animal.”

On the current landscape Cahill noted the separation at the top. “We’re seeing an incredible level of tennis at the moment, with Carlos 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, to watch and copycat a little bit, to work a little bit harder and to work on the things they are working on, do what everyone does and that’s try to be as good as the best.

“We are very fortunate as coaches and it has been a wonderful journey so far.”

Frances Tiafoe and Holger Rune meet again in Cincinnati with live coverage available on TennisChannel.com. The match is scheduled to start at 11:00 a.m. ET on Wednesday, August 13. This pair’s return to the same venue produces immediate storylines because of what happened here a year ago.

Tiafoe arrives as the No. 14-ranked American; Rune is No. 9. Their meeting in Cincinnati is the first match-up in this men’s tournament between Top 15 players. Last year the two played in the semifinals at this event, a match Tiafoe won 4-6, 6-1, 7-6 (4). The result nearly went the other way: Rune led 5-2 in the third set and “had held double match point a few games later with Tiafoe serving at 4-5, 15-40.” That recovery remains a defining moment for Tiafoe at this event.

Tiafoe’s history at this time of year underlines his form here. He reached the biggest final of his career at this tournament a year ago and has also reached both of his career Grand Slam semifinals at the US Open, in 2022 and 2024. Rune comes in with the higher ranking and the memory of coming close to knocking Tiafoe out last year.

The match carries implications for both players in Cincinnati. For Tiafoe, a win would move him another step toward repeating last year’s deep run. For Rune, it is a chance to avenge a narrow loss in identical surroundings.

Carlos Alcaraz returns to court Wednesday night in Cincinnati aiming to extend a remarkable run. Yesterday afternoon, Alcaraz moved past fellow 22-year-old Hamad Medjedovic, 6-4, 6-4, to reach 50 wins for the season and to become the only man to record 50 or more wins in each of the last four years. Tonight he will seek his 51st win of 2025 in a fourth-round meeting with 22-year-old Luca Nardi.

Nardi reached this stage after entering the main draw as a lucky loser and fighting his way into the fourth round. He is best known for stunning then-No. 1 Novak Djokovic at Indian Wells last year and arrives in Cincinnati with momentum and confidence. The Italian pushed Alcaraz to three sets in their only previous meeting, a 6-1, 4-6, 6-3 victory for the Spaniard in Doha earlier this year, showing he can extend rallies and trouble the top players.

The pairing presents a clear contrast: Alcaraz arrives having just reached the 50-win milestone and playing with the consistency that produced that mark across multiple seasons. Nardi has the underdog profile of a lucky loser who has turned opportunity into results, including his signature win at Indian Wells.

The match will be watched closely as Alcaraz attempts to convert recent form into another late-night victory, while Nardi looks to repeat the level that has produced upsets and that pushed their Doha meeting to three sets. The result will shape the bottom half of the draw as the tournament moves deeper into the second week.