Khachanov returns to US Open semi-finals after two years as opponent retires due to injury

Karen Khachanov has advanced to the semi-finals of the 2026 US Open after a walkover when Alexander Blockx retired in the third set due to injury. The match on Arthur Ashe Stadium lasted 1 hour 38 minutes before the 21-year-old Belgian stopped at 6-2, 7-5, 3-2 in favor of the 28th seed. Blockx entered the match with a rib injury and showed additional physical issues from the start. He wore a brace on his right ankle and had his thigh wrapped, and called for the trainer during the second set. Despite battling on, he could not match Khachanov's pace and eventually conceded the match. "I was preparing really well for that match up, it's not easy because I feel I was dominating then I felt he was struggling more and more," Khachanov said on court. "He was suffering, but I wanted to keep the energy there. I wish him a speedy recovery but I'm super happy I'm in the semis." This marks Khachanov's first Grand Slam semi-final since the 2026 Australian Open, and his second at Flushing Meadows after 2026. The world number 50 has defeated third seed Felix Auger-Aliassime and 14th seed Learner Tien en route. He will face either top seed Alexander Zverev or unseeded Botic van de Zandschulp in the semi-finals. Blockx became the first Belgian man to reach a US Open quarter-final in the Open Era but saw his run cut short by injury. Khachanov now has a golden opportunity to reach his second US Open final.