Shoulder injury brings Novak Djokovic's US Open to abrupt end

Novak Djokovic's hopes to repeat as the U.S. Open champ were dashed by a left shoulder injury, and his Grand Slam nemesis, Stan Wawrinka. Djokovic, the No. 1 seed who had already won the Australian Open and Wimbledon this year, retired after dropping the first two sets and getting broken in his second service game...