Defending champion Aryna Sabalenka received a walkover into the U.S. Open semi-finals on Tuesday after Marketa Vondrousova was forced to withdraw from their last eight showdown due to a knee injury, organisers said on Tuesday, Reuters reported.

Vondrousova, the 2023 Wimbledon champion, had impressed in New York with upset victories over seventh seed Jasmine Paolini and ninth seed Elena Rybakina, but her run came to a painful end after she pulled up in practice earlier on Tuesday.

ESPN showed footage of the 26-year-old bending over in pain after hitting a forehand, before leaving practice in tears, and she later confirmed the injury, according to Reuters.