Caroline Wozniacki has been accused of racism after stuffing her top and skirt with towels to impersonate fellow tennis player Serena Williams during a match in Brazil.
The 22-year-old Dane pranced around the court to laughter and whistles from the crowd as she played a point against Maria Sharapova in the exhibition match in Sao Paulo.
But the former world No.1 has now attracted criticism on social media for impersonating the Grand Slam champion, who is also her friend.
On Tumblr, one blogger wrote: "This isn't "harmless fun" as one article described it. its racist. out and outright racism. mocking and making fun of the bodies of black women for a laugh? real funny, stupid white girl. real real funny.'
Another blogger wrote: "It may have been done in "jest," but I love how people can can turn a black woman's body and sexuality into a caricature. However, we should not have the autonomy to celebrate any successes of our own."
An article on the website feministing.com said: "... given the history and current-day context of racialized standards of beauty, and the hypersexualization of people of color, when a white woman makes fun of a black women's body, especially in a way that hypersexualizes her and draws on the stereotype of black women's big butts, it's racist."
Hass Dellal, the executive director of the Australian Multicultural Foundation, said Wozniacki probably did not intend her actions to be racist, but they could be interpreted as such.
"It's quite inappropriate to be mocking or making jest of people's physical shape or image, especially when it's such an issue with young people today," he said.
"I can see how some people could interpret that, simply because of stereotyping, as being racist.
"A role model should be acting more responsibly. It's quite inappropriate to mock a person's body shape and image.
"Stereotyping can lead to all forms of discrimination."
It's not the first time Wozniacki has imitated her friend Williams during an exhibition match.
She performed a similar stunt in December last year, when she also danced around the court to a Rihanna song.
And Andy Roddick has also impersonated Williams by stuffing towels down his pants on court.
Williams is known for referring to her figure.
The day before the exhibition match in Brazil, which Williams also attended, she tweeted: "Hummmmm do they make Brazilian bikinis for ummm well..... Me???".