Tennis fan J.K. Rowling takes down a Serena Williams hater on Twitter

J.K. Rowling is a huge Serena Williams fan, watched her Wimbledon win, and took down a Serena hater on Twitter.

Troll in the dungeon!

After Serena Williams beat Garbine Muguruza in straight sets to win her sixth Wimbledon title and 21st career Grand Slam, both her biggest supporters and haters came out of the woodwork on Twitter. 

One of her biggest fans is author J.K. Rowling, of Harry Potter fame, who took a break from copy edits to tweet throughout the championship match.

Over the course of the match, she became a fan of Muguruza as well, but it's clear Serena has Rowling's heart. And after a hater emerged on Twitter with an unoriginal and unnecessary comment about Williams' physique, Rowling tossed him the ol' Expelliarmus in the form of a pretty well thought-out response. 

.@diegtristan8 "she is built like a man". Yeah, my husband looks just like this in a dress. You're an idiot. pic.twitter.com/BCvT10MYkI

— J.K. Rowling (@jk_rowling) July 11, 2015

Rowling also took the time to admit that her years of writing books have...limited her tennis skills a bit.

.@xcodelario My tennis game is non-existent. Feeble little arms like a T-Rex due to years of typing, typing, typing. Strong fingers though.

— J.K. Rowling (@jk_rowling) July 11, 2015

• WERTHEIM: Serena continues dominance with sixth Wimbledon title

- Jeremy Woo