Jannik Sinner and Naomi Osaka both produced commanding displays on Wednesday to reach the semi-finals of the U.S. Open, underlining their credentials on tennis’s biggest stage.

Defending champion Sinner swept aside compatriot Lorenzo Musetti 6–1, 6–4, 6–2 in the first-ever all-Italian men’s Grand Slam quarter-final. The world number one, already this year’s Australian Open champion, extended his hardcourt winning streak to 26 matches and will next face Canada’s Felix Auger-Aliassime.

“It was a good performance, I was very solid, I started well,” Sinner said after the late-night clash. “Obviously we know each other well, but when we shake hands, everything is fine. Playing here, in this stadium, means a lot to me.”

Sinner’s thunderous hitting saw him seize control from the outset, racing to a 5-0 lead in the opening set. Musetti briefly threatened in the second, but Sinner’s composure and relentless power ensured a straight-sets victory and another step toward defending his title.

On the women’s side, Naomi Osaka continued her remarkable resurgence by defeating Karolina Muchova 6–4, 7–6(3), booking a semi-final showdown with eighth seed Amanda Anisimova.

The 23rd seed, returning from a maternity break last season, has now stretched her unbeaten record in Grand Slam quarter-finals to 5-0. Osaka, who last lifted a major trophy four years ago, said her journey back had deepened her love for the sport.

“I learned I loved tennis way more than I thought I did,” Osaka said. “It’s like a video game—you lose a level, restart, and keep going until you eventually win. I wouldn’t trade it for the world.”

Muchova, hampered by a leg issue after long early-round battles, still tested Osaka with her variety, even leading 5-4 in the second set before Osaka fought back to clinch the tiebreak.

Looking ahead, Osaka praised her next opponent, who stunned world number one Iga Swiatek earlier in the day. “She’s unpredictable and very tough to play. To beat Iga here is a huge achievement. Tomorrow will be a really tough match.”

Together, Sinner and Osaka lit up Arthur Ashe Stadium with performances that blended dominance and resilience, setting up semi-finals full of intrigue as the U.S. Open enters its final weekend.

Semi-Final line-ups

Women’s Singles:
05/09/25 @ 02.00 am A.Sabalenka (1) v J.Pegula (4)
05/09/25 @ 03.30 am N.Osaka (23) v A.Anisimova (8)

Men’s Singles:
05/09/25 @ 10.00 pm N. Djokovic (7) v C.Alcaraz (2)
06/09/25 @ 02.00 am J. Sinner (1) v F.Auger-Akiassime (25)