The No. 3 seed Iga Swiatek ended the Cincinnati Open with a 7-5, 6-4 victory over Jasmine Paolini, using a markedly improved serve to secure the title. Time after time Swiatek produced serves in the 110- to 115-m.p.h. range, approximately the 185 k.p.h. mark her coach Wim Fissette had envisioned when their partnership began last fall.

She hit eight aces and at least that many service winners, often at pivotal moments. Down 2-3 in the first set she produced two unreturnable serves to hold; at 6-5 she closed the set with three service winners and an ace. In the second set she fended off a break point at 4-3 with a service winner, held with an ace and ended the match with an ace out wide.

Swiatek acknowledged trade-offs in pursuit of power: she committed seven double faults and made 57 percent of her first serves, and she did not consider the night perfect. “I couldn’t even toss well,” she said with a laugh. “It was a love-hate relationship [with her serve] today.”

She described the process with Fissette plainly. “I’m always this kind of player who needs to see the proof,” she said. “When I started working with Wim, I didn’t believe that I can serve 185 [kilometers per hour] and 180 consistently. So I think he helped me with reaching this higher speed…I just kind of needed to believe it.”

Her season has shifted markedly: after failing to win during the clay swing she claimed Wimbledon and now Cincinnati, titles on grass and quick hard courts that she had once struggled to master. She credited the broader team and her mental work. “Maybe I wasn’t committing to my serve for some part of the season,” she said. “I was focusing on the right things,” she added. “Maybe not everything was perfect. Mentally I was there to just play the best tennis that was possible at that moment.”

“Thank you for forcing me to become a better player,” Swiatek said to Fissette afterward. With the title she moves from No. 3 to No. 2 in the rankings and seedings at the US Open, removing a potential semifinal meeting with No. 1 Aryna Sabalenka.

Jannik Sinner withdrew from the Cincinnati Masters final against Carlos Alcaraz after just five games, visibly overcome by illness and emotion. He apologised to the Cincinnati crowd as he slumped in his chair and was unable to continue the match. Alcaraz went on to claim the latest ATP Masters 1000 title, but the victory was tempered by concern for his rival.

Sinner had been due to play in the revamped US Open mixed doubles event on Tuesday, having been paired with women’s world No 2 doubles player Katerina Siniakova, but his appearance in that event is now in serious doubt. The incident also followed a match 48 hours earlier in which world No 3 Alexander Zverev struggled with illness against Alcaraz, prompting questions about a possible virus circulating at the tournament.

“Two of the three top players in the world are ill before the end of the tournament and you have to be concerned that there is some kind of bug going around,” said Sky Sports commentator Jonathan Overend.

“He was hugely apologetic to the crowd. That will have really, really hurt him.

“One thing is for sure, he is not going to play in New York tomorrow in a glorified exhibition. That has not been confirmed yet, but Sinner won’t be playing. That must be inevitable now”

Former Grand Slam doubles champion Ryan Harrison offered a more optimistic timetable for recovery, saying Sinner would seek medical attention immediately and noting the gap before the US Open singles defence begins on Sunday.

“From what it sounds like, he thought he could not win but he went out there to try and make something that was watchable, but if you can’t do it, there’s nothing else you can do,” said Harrison.

“He will be straight to the doctors. It’s not something I would be overly worried about, given that the US Open is two weeks off and you get a day off after each match.

Heartbreaking

“By the time he recovers this week, gets through the opening match, then in 10 days he will be fully recovered at the latter stages.”

Alcaraz acknowledged the circumstances after lifting the trophy. “It’s not the way I want to win matches or the trophy. I just have to say sorry,” said Alcaraz.

“I know and understand how you [Sinner] feel right now. I can’t say anything you don’t know.

“You are a true champion and I’m sure you will come back better, even stronger. You always do and that’s what true champions do. Sorry, and come back stronger.”

Alcaraz is due to play in the US Open mixed doubles against Emma Raducanu on Tuesday, while confirmation is expected that Sinner will not take part in the mixed doubles match.

Jannik Sinner was forced to retire from the Cincinnati Masters final against Carlos Alcaraz after just five games, bringing immediate concern about his fitness ahead of the US Open.

The world No 1 appeared unsteady on his feet from the start and left the court in tears. Early signs suggested he was struggling with his right hip or thigh, and he conceded the match after being broken for a third time while 5-0 down in the opening set.

“I tried, but I can’t. I’m sorry for the fans,” Sinner said the medics as he confirmed he could not continue.

Sinner apologised to the crowd and explained the issue in more detail after the match. “I’m super sorry to disappoint you,” he said. “From yesterday, I didn’t feel great, I thought I would during the night, but it got worse.

“I tried to come out and make it a small match but I couldn’t handle more. I’m very sorry for all of you.

“I know some of you on Monday have to work or do something else, so I’m really sorry.

“I’m sorry to disappoint but sometimes it’s like this and we have to accept it.

“It’s been one of the hottest tournaments we have faced, so thank you for all of the support and organisation.

“Of course, Carlos congrats. Another title. Not the way you wanted to win, but it’s amazing what kind of season you’re producing. You and your whole team are doing amazing.

“Keep it up. I wish you only all the best for the U.S. Open and the rest of the season.”

Former Grand Slam doubles champion Ryan Harrison, who was commentating, suggested the problem could be an illness related to recent cases in the field. “We hope it’s nothing serious. We hope it’s just an illness. It could be due to fatigue. We saw it with Alexander Zverev,” he said. “It could be a stomachache because he was reaching down there.

“Sometimes an illness goes around the locker room. We have seen it before and maybe that is what it is this time. We wish Jannik well as the US Open is just a few days away now.”

Sinner’s early exit hands the Cincinnati title to Alcaraz but leaves a question mark over the Italian’s ability to compete at the US Open unless the issue resolves quickly.