Karen Khachanov reaches US Open semifinals after Alexander Blockx retires

Unseeded Russian Karen Khachanov advanced to the US Open semifinals on Wednesday at Arthur Ashe Stadium after Alexander Blockx retired from their match. Blockx, the No. 28 seed from Belgium, struggled throughout the contest with a lingering rib injury sustained prior to the Round of 16. After losing the first two sets 6-2 and 7-5, Blockx required multiple medical timeouts for foot and torso issues. He ultimately decided to stop playing while trailing 3-2 in the third set. This outcome marks the second time in his career that Khachanov has reached the semifinals at the US Open. Khachanov will now await the winner of the quarterfinal match between No. 1 seed Alexander Zverev and unseeded Botic Van De Zandschulp. For Blockx, the loss ends his deepest run at a Grand Slam tournament and the furthest advancement by a Belgian player at the US Open.

• 12:25 AMESPN Tennis — Khachanov, up 2 sets, advances to US Open semis when Blockx retires
• 10:54 PMYahoo Sports — Unseeded Russian Karen Khachanov advances to US Open semifinals after hobbled No. 28 seed Alexander Blockx retires in third set