After impressing in their US Open mixed doubles opener, Serena Williams and Carlos Alcaraz were knocked out in the quarter-finals.

The pair had turned on the style to beat Erin Routliffe and Lloyd Glasspool in their first match – Alcaraz's return to action after a lengthy spell on the sidelines – but they could not repeat that against Belinda Bencic and Flavio Cobolli.

Instead, Williams and Alcaraz suffered a 5-4 (7-4) 4-1 defeat to the fourth-seeded pair.

There was nothing to split the teams in the first set, with Bencic and Cobolli finding their groove in the tie-break to reel off the final four points and take the lead.

But while Williams and Alcaraz held off two break points in their first service game of the second, they could not repeat that trick in the fourth game, with Bencic and Cobolli booking their place in the semi-finals.

Down to ! pic.twitter.com/NE45zSBlXo

— US Open Tennis (@usopen) August 25, 2026

They will face Elina Svitolina and Gael Monfils, who got the better of Katerina Sinikova and Henry Patten thanks to a breaker, winning 5-4 (8-6) 4-5 (3-7) 10-8 in a tightly contested match.

On the other half of the draw, Mirra Andreeva and Andrey Rublev found a way past Diana Shnaider and Casper Ruud.

After a strong first set, they had to dig deep, winning 4-1 4-5 (9-11) 10-5 in one hour and 14 minutes.

And rounding out the semi-finals are Karolina Muchova and Jakub Mensik, who earned a 4-1 5-3 victory over Emma Navarro and Tommy Paul.