NEW YORK (AFP) — Karen Khachanov set up a US Open semifinal duel with Casper Ruud when he battled past "devastated" Nick Kyrgios in a big-hitting five-setter, shattering the Australian crowd-pleaser's dreams of a maiden Grand Slam title.

Russian 27th seed Khachanov triumphed 7-5, 4-6, 7-5, 6-7 (3/7), 6-4 over the Wimbledon runner-up to make the last-four at a major for the first time.

Earlier, Norwegian fifth seed Ruud defeated Italy's Matteo Berrettini 6-1, 6-4, 7-6 (7/4) to make his second Slam semifinal of 2022 having finished runner-up to Rafael Nadal at the French Open.

Khachanov fired 30 aces and a total of 63 winners past Kyrgios.

"I did it, guys. Finally, you are showing me some love," Khachanov told the mostly pro-Kyrgios crowd on Arthur Ashe Stadium.

"It was a crazy match I was expecting it would be like this. I'm ready to run, to fight, to play five sets. We played almost four hours and that's the only way to beat Nick."

The Russian said he had "nothing to lose" when he faces Ruud on Friday.

"I would like to win it," said Khachanov, who lost to the Norwegian on clay in Rome in 2020 in their only previous meeting.

"But as deep as you go the expectations rise up. I did the step forward, I made my first semifinal and I think I have nothing to lose."

"I just want to go for it and be ready for the next match and hopefully it will be a good one."

Kyrgios, who had knocked out defending champion Daniil Medvedev in the Last 16, hit 31 aces in his 75 winners.

However, his unforced error count of 58 was almost double the 31 of Khachanov.

"I'm devastated. It's heart-breaking for me and everyone," Kyrgios said.

"I feel like I have let so many people down."

After Kyrgios had levelled the contest just after midnight with a dominant tiebreaker, he allowed Khachanov to break for a 1-0 lead in the final set.

Kyrgios then failed to convert break points in the second and fourth games and his chance was gone.