Novak Djokovic out of U.S. Open after hitting lineswoman with tennis ball

It wasn’t another player who ended Novak Djokovic’s perfect season in the fourth round of the U.S. Open Sunday. It was his own imperfect behavior – an angry smack of a tennis ball that inadvertently hit the throat of a linesperson and defaulted the world’s No. 1 player from the first Grand Slam tournament in eight months.