By JOHN PYE MELBOURNE, Australia (AP) — Instead of starting the defense of his Australian Open title on Monday, Novak Djokovic was on his way home, a stunning and unprecedented end to his run of success at Melbourne Park. Djokovic has won nine of his 20 Grand Slam trophies at the Australian Open — including three in a row — and was scheduled to play in the main stadium to conclude Day 1 of the tournament.