The United States Open final between the tennis legend Serena Williams and Naomi Osaka, a rising star in her own right, could have been a celebration of talent and determination, regardless of the outcome.

Instead, the match on Saturday will be remembered for what Williams charged were “sexist” code violations against her by the chair umpire, who penalized her for verbal abuse after she called him a “thief.”

Osaka went on to win the match in two sets, 6-2, 6-4, but she was also upset and apologized to the crowd and Williams’s fans.

Reactions on social media largely focused on the umpire, Carlos Ramos, for penalizing Williams for behavior that critics said would ordinarily result in just a warning for other players.