Unseeded Russian Karen Khachanov advances to US Open semifinals after hobbled No. 28 seed Alexander Blockx retires in third set

Unseeded Russian Karen Khachanov advances to US Open semifinals after hobbled No. 28 seed Alexander Blockx retires in third set

Khachanov advances to face the winner of Wednesday’s prime-time match between No. 1 seed Alexander Zverev and unseeded Botic Van De Zandschulp.