Barbora Strycova slammed Serena Williams' claims of sexism in the US Open final as "the biggest bulls--t."

In an interview with the Czech publication Sport.cz, Strycova says Serena's claim that chair umpire Carlos Ramos made a sexist ruling docking her a game during Naomi Osaka's 6-2, 6-4, victory in the US Open final is wrong.

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Strycova suggests Williams realized she was going to lose the final and resorted to playing the controversy card as a tactical tool.

"How did she fight [for] women's rights? That's the biggest bulls--t," Strycova told the website. "The umpires do not take into account whether they are male or female. I personally am a person who receives a warning very often, so I can draw on my experience. I said one word and I got a fine at the US Open."

Strycova suggests it was shameful US Open and WTA officials issued statements of support for Serena after the final and questioned if that means there are two different sets of rules: one for Serena and one for the rest of the players.

"When Serena is playing the next match, will there be other rules?" Strycova said. "Why should everything change when the umpire acted according to the rules? The WTA defense surprised me. Will rules change in Serena's matches? If it's like this let me know.

"Serena is an incredible player and champion, but I do not [appreciate] that style of losing and spoiling that young girl [Osaka's victory] is terribly sad. That was terrible."

The veteran Czech said Williams' behavior berating chair umpire Ramos and calling out referee Brian Earley overshadowed Osaka's overwhelming performance in her maiden major final.