Former Wimbledon champion Petra Kvitova was upset in the first round of the Australian Open by Thailand's Luksika Kumkhum, 6-2, 1-6, 6-4.
Luksika, playing just her second Grand Slam tournament, broke the sixth-seeded Kvitova in the eighth game of the third set after the Czech player hit a double-fault.
Kvitova broke back to make it 5-4, but then dropped her serve in the last game.
The speedy Thai player, who plays with a two-handed forehand and backhand, reached the second round of the Australian Open last year.
Kvitova lost in the first round of a Grand Slam for the first time since the 2011 U.S. Open, months after claiming the title at Wimbledon.