Getty Images Serena Williams stole the show at the royal wedding after-party. The tennis champion reportedly dominated at beer pong — and even came prepared for the boozy showdown as she wore trainers underneath her Valentino gown. A championship-winning athlete is the last person you should challenge to a game of beer pong — but that did not stop revellers at the royal wedding after-party.See the rest of the story at Business InsiderNOW WATCH: NBA ref explains the difference between flopping and selling a callSee Also:Amazon is making it harder and harder to quit PrimeRoger Federer just became the world's No.