Defending champion Alcaraz was sensational against Alexander Zverev of Germany as he won 6-3, 6-2, 6-4.

The Spaniard extended his winning streak to 12 at Grand Slams with the latest triumph.

Alcaraz, who won the Wimbledon this year after an epic final against Novak Djokovic, won all his four break points, while saved all five against him and will meet Russian Medvedev next.

Having beaten the Russian at the Indian Wells and Wimbledon this season, Alcaraz will be going into the match high on confidence.

Medvedev, meanwhile, reached the last four after defeating compatriot Andrey Rublev 6-4, 6-3, 6-4.

Despite the scoreline, Rublev, who is the godfather of Medvedev's daughter, put up a fight and broke Medvedev five times.

Medvedev was trailing in all three sets but the third seed held on to reach the third US Open semi-final.

"Andrey, when he started the match, I think he won 10 points in a row, hitting on the line," said Medvedev.

"I was like, 'OK, I'm going to have to be better than I am right now.'"

The third seed went on to heap praise on his next opponent.

"It needs to be 11 out of 10 because that's how Carlos is, very strong," Medvedev said.

"Even here, he lost one set [to Daniel Evans in the third round], but I watch some matches, sometimes on break points he runs for the passing shots. Incredible stuff."

Among women, Sabalenka continued to show why she is the deserving world number one in waiting, with a dominant 6-1, 6-4 win against Zheng Qinwen of China.

The Belarusian is yet to lose a set in the US open this year has reached the fifth Grand Slam semi-final in a row, including all four this season.

She will be up against home favourite Madison Keys after the American advanced with a 6-1, 6-4 victory against reigning Wimbledon champion Markéta Vondroušová.

Vondroušová, who beat Tunisian Ons Jabeur at SW9, could not make it back-to-back Slam titles as the superior Keys, who saved all nine break points was hard to contain.

American Jessica Pegula is hoping to make up for the singles and women's doubles disappointment as she teamed up with compatriot Austin Krajicek for a 6-7, 6-1, 10-3 mixed doubles semi-final win against Taylor Townsend and Ben Shelton of the United States.

Earlier, Pegula and teenage compatriot Coco Gauff went down Hsieh Su-wei of Chinese Taipei and Wang Xinyu of China 6-7, 6-3, 4-6.

Laura Siegemund of Germany and Vera Zvonareva of Russia reached the women's doubles semi-final despite going down in the first set against Victoria Azarenka of Belarus Beatriz Haddad Maia of Brazil.

Siegemund and Zvonareva put on a spirited performance to win 5-7, 7-5, 6-4.