Martina Navratilova, an 18-time Grand Slam singles champion, says Serena Williams was wrong in her outburst at the US Open women's finals even though she agreed there is a double standard. Writing in an opinion article for the New York Times, the Czech-born American said a higher standard needed to be observed when Serena called umpire Carlos Ramos a thief and was penalised a key game in the second set.

"We cannot measure ourselves by what we think we should be able to get away with," Navratilova wrote. "In fact, this is the sort of behavior that no one should be engaging in on the court." Serena said she was punished for saying something where men have said far worse without incurring such a penalty.