Nike TV Commercial, 'Just Do It: Serena Williams'

A younger Serena Williams starts her serve, while her coach tells her to pretend like she's at the U.S. Open. A present day Serena completes the service and continues play as her coach's voice guides her through the match. As the shot alternates from a home video of the younger tennis superstar to footage of her competing at the Open, Nike says its only crazy until you do it.