Petra Kvitova has admitted that she is unable to explain her first-round defeat to Luksika Kumkhum at the Australian Open.
The Czech sixth seed was beaten in three sets by the world number 88 on Monday in arguably the biggest shock of the tournament so far.
"I really want to know what happened out there," the WTA's official website quotes Kvitova as saying. "Unfortunately I didn't play well. I didn't play my game and what I was really trying to work on all off-season.
"It was a great off-season and I was really excited to be here, but I probably wanted it too much, and then everything just fell down."
Kvitova reached the second round of last year's tournament before losing to Britain's Laura Robson.
