Serena Williams isn't afraid to cut loose. The 36-year-old Grand Slam champion and cover star of American Vogue's February issue recently showed off her dance moves on the runway at Palm Beach International Airport to the sounds of Rihanna and N.E.R.D.'s infectious dance track "Lemon." In the fun clip, the new mum twerks like no one's watching and serves up a mean racket using a lemon. "Serving 🍋🍋🍋!!!! You killed it," Pharrell wrote on Instagram. Watch the video above to see Serena, who was also the twerking champion of Beyoncé's "Sorry" music video, in action. We wonder if Serena got down like this at her wedding with her husband Alexis Ohanian.