Aryna Sabalenka said Tuesday that she wants to cap off a stellar year by returning to the top of the world rankings.

"I'm too far away from that level," he said. "I hope I'll reach it one day, but it's really impossible," said Alcaraz.

"It was a huge thing when I played him for the first time," said the world number three. "The other times for me were kind of a nightmare."

Tennis great Roger Federer said on Wednesday staying involved with the sport in retirement helped him avoid feeling "like an alien" ahead of this week's Laver Cup tournament in Berlin.

Sinner had explained that the slight traces of clostebol had originated from a spray used by a member of his staff to treat a cut finger.

Rafael Nadal will not compete at the Laver Cup next week in Berlin, said the 22-time Grand Slam champion in a statement released by tournament organisers on Thursday.

With Roger Federer retired and Rafael Nadal struggling to get back on court due to injuries, Novak Djokovic was the last man of that golden generation standing at Flushing Meadows, but the Serb crashed out in the third round to Australian Alexei Popyrin.

Jannik Sinner produced a brutal display of baseline power as he became the first Italian man to win the US. Open with a 6-3, 6-4, 7-5 win over American Taylor Fritz in the final on Sunday.

"I'm speechless right now. So many times I thought I was so close to get the US Open title. It has always been a dream of mine and finally I got this beautiful trophy," said Sabalenka.

Frances Tiafoe blamed his heartbreaking five-set US Open semi-final defeat to Taylor Fritz on cramping after his "body shut down".

Taylor Fritz fought back to defeat compatriot Frances Tiafoe at the US Open on Friday, becoming the first American man to reach a Grand Slam final in 15 years.

Italian top seed Jannik Sinner took down ailing Briton Jack Draper 7-5, 7-6 (7/3), 6-2 to reach the US Open final on Friday, overcoming muggy conditions in a chaotic match at Arthur Ashe Stadium.

Pegula has now won 15 of 16 matches on the US summer hard court swing which saw a title in Toronto and defeat in the Cincinnati final to Sabalenka.

Sabalenka sent down 34 winners to the 13 of the 23-year-old American in the tie.

Medvedev still leads their head-to-head 7-6, although the Italian Sinner has won six of their last seven meetings.

World number one Jannik Sinner reached his first US Open semi-final on Wednesday with a four-set victory over 2021 champion and two-time runner-up Daniil Medvedev.

Jessica Pegula became the fourth American to reach this year's US Open semifinals on Wednesday by stunning world number one Iga Swiatek as Jack Draper broke through to his first Grand Slam last-four.

Sinner is the only top-four player left in the men's draw following the exits of Novak Djokovic, Carlos Alcaraz and Alexander Zverev.

Emma Navarro reached her first Grand Slam semi-final at the US Open on Tuesday with a straight-sets victory over Paula Badosa whose challenge dramatically collapsed.

The 23-year-old Italian is the only man to have made the quarter-finals of all four majors this season.