World No. 6 Petra Kvitova says self-imposed pressure got the best of her in a, 6-2, 1-6, 6-4 upset loss to Thailand's Luksika Kumkhum in the Australian Open first round. It was Kvitova's first opening-round loss in Melbourne since her 2009 debut.

“Unfortunately I didn't play well,” Kvitova said. “Probably I wanted too much, and then everything just fell down. She play well, of course. But I didn't serve [well]. Probably before my match I was nervous. Every time my legs are not moving well, so that's the thing when I started to feel it.  Normally after like set or something it's a little bit better. But it wasn't today. So I was lucky that I won second set probably.

"I had a great pre‑season. I work very hard. I had great matches on my back and probably I put a lot of pressure on my back."