J.K. Rowling has been showing extreme support for tennis champion Serena Williams since recently winning the Wimbledon trophy.

Rowling praised the star athlete several times via Twitter on Saturday, July 11 and even slammed a Twitter user that made a nasty comment about Williams' body frame, Us Weekly reports.

The twitter user @diegtristan8 tweeted that Williams was "built like a man" and Rowling responded with a snarky comment and tweeted a photo of the tennis champion looking stunning in a red mini dress.

Check out Rowling's Twitter comeback below.

Serena Williams has yet to respond publicly to the Twitter user. Us Weekly reports that the "Harry Potter" author is known for clapping back at Twitter users that have tweeted nasty comments.

Back in September, Rowling fired back at a homophobic Twitter user that expressed his opposition towards a homosexual "Harry Potter " character.

"Once u revealed Dumbledore was homosexual I stopped being a fan," the homophobic Twitter user, Frank Fraticelli, wrote online before he deleted his account. "Nice how u blindsided us with that one. Enjoy your billion $."

Rowling then responded with her own pointed tweet referencing homophobic Stagecoach founder Brian Souter. "I advise you to start following Brian Souter at once. He's much more your kind of person," she tweeted in response."

According to E! News, Souter funded a campaign "to maintain a teaching ban in schools regarding the acceptance of homosexuality." Rowling first introduced the "HP" character Dumbledore as gay during an audience Q&A in 2007, People reported.

When a member of the audience asked Rowling if Dumbledore had ever been in love, the bestselling author responded, "I always thought of Dumble as gay. Dumbledore fell in love with Grindelwald, and that added to his horror when Grindelwald showed himself to be what he was." Following her tweet to Fraticelli, Rowling then tweeted a thankful message to her supporters.