John McEnroe enters the court to accept the challenge from Novak Djokovic, and proceeds to serve, after Djokovic easily defeated Radek Stepanek in the fourth round of the 2009 U.S. Open. (Novak Djokovic (4) def. Radek Stepanek (15) 6-1, 6-3, 6-3). Filmed from club tier in Arthur Ashe stadium, Flushing, NY.