Defending US Open champ Sabalenka returns to semifinals with walkover win against Vondrousova

According to the U.S. Tennis Association, Vondrousova is the first woman to give her opponent a walkover — the term for when a tennis player withdraws from a match before it begins — at the U.S. Open in the quarterfinals or later since 1988, when Steffi Graf advanced to the final when Chris Evert di...