Unseeded Karen Khachanov reached his third Grand Slam semifinal -- and first since 2023 -- when No. 28 Alexander Blockx stopped playing midway through the third set of their US Open quarterfinal match Wednesday after Khachanov had won the first two.
Blockx had his upper left leg wrapped and received treatment on both his lower leg and back as well. He stopped playing with Khachanov ahead 6-2, 7-5, 3-2.
Khachanov, who reached the semis at the U.S. Open in 2022 and the 2023 Australian Open, will play top-seeded Alexander Zverev or Botic Van De Zandschulp in one semifinal match Friday.
No. 8 Ben Shelton and No. 11 Frances Tiafoe will square off in an all-American semifinal match.
The Associated Press contributed to this report.