J.K. Rowling defends Serena Williams after Twitter troll's 'manly' jibe

America's world No 1 Williams moved a step closer to becoming the greatest women's tennis player of all time with a 6-4 6-4 victory over 20th seed Garbiñe Muguruza in the Wimbledon final.

In winning her sixth title on Centre Court at the All England club and her 21st Grand Slam title, Williams holds all four Grand Slams - the Australian Open, the French Open, Wimbledon and the US Open.

But Harry Potter author Rowling found herself involved in a post-final dust-up on social media with a bloke called Rob who said Williams was only successful because she was "built like a man"'.

After Rowling praised Williams, the Twitter user responded by writing: "..ironic then that main reason for her success is that she is built like a man.”

Rowling quickly retorted: " ..she is built like a man". Yeah, my husband looks just like this in a dress. You're an idiot."

Elsewhere, the reaction was largely positive with Serena only one Grand Slam short of Steffi Graf's haul of 22 titles in the Open era. She will become the first player since Graf in 1988 to complete a calendar sweep of all four Slams if she defends the US Open next month.

Some prominent Americans - including Hillary Clinton and Kobe Bryant - were particularly enthused by watching Williams prevail on Centre Court. At 33, she is the oldest winner of a Grand Slam in the modern era.