British novelist JK Rowling jumped to Serena Williams's defence at the weekend after a Twitter user described the Wimbledon champion as 'manly'.
The triumph was a historical one for Williams as she became the oldest ever Wimbledon champion and is on course to complete a calendar Grand Slam following victories at the Australian and French Opens.
Despite Williams's success, one Twitter user decided to criticise the tennis star by claiming that she was "built like a man" - a comment which Rowling, who is best known for the Harry Potter series, did not take kindly.
In response, the 49-year-old posted a photo of Williams in a figure-hugging red dress and wrote: "Yeah, my husband looks just like this in a dress. You're an idiot."