Kvitova puts on confident display in Birmingham

BIRMINGHAM, England (AP) - Two-time Wimbledon champion Petra Kvitova produced her most encouraging result since returning from a knife attack to advance to the quarterfinals of the Aegon Classic, a Wimbledon warmup tournament.

The left-handed Czech hit 25 winners with 11 unforced errors as she easily beat fellow wild card Naomi Broady of Britain 6-2, 6-2 on Wednesday.

Kvitova only recently returned to action after suffering a serious injury to her left hand - when she was stabbed by an intruder last year at her home in the Czech Republic - playing two matches on clay at the French Open.

"I have a little bit different view for tennis right now and for matches," Kvitova said. "When I'm playing, I'm just a little bit more relaxed, I think, and I'm not as nervous as I was before."

There were few signs of obvious discomfort in the hour-long match for Kvitova.

"When I started playing (again) we had a discussion with the coach as to whether I should change something - a bigger grip, or a softer grip. But I decided I don't want to change anything," the seventh-seeded Kvitova said.

"I kept the same grip. I am glad I made that decision. If I had changed anything, even small, in the hand or in the racket, it might bring injuries. With different techniques it becomes tough.

"It's still improving. I am missing a few things, but I am getting there. It could take six months or a year. No one can tell how long it will take."

Kvitova hit some raking ground strokes, gradually made some enterprising net plays, and widened her range of tactical choices as her confidence grew. There were some double faults, but when Kvitova needed to serve well she did so, and at the end she was loudly cheered.

"I am trying to find my best each time I play," Kvitova said. "I am here to play tennis and on the grass that I love. My tournament isn't finished yet, for which I am really glad."

Kvitova will play either Kristina Mladenovic, the fifth-seeded French player who ended Garbine Muguruza's French Open title defense 2 1/2 weeks ago, or 31st-ranked Chinese Shuai Zhang.

Barbora Strycova, the eighth-seeded Czech and twice a runner-up here, was beaten 6-3, 3-6, 6-1 by 21-year-old Australian Ashleigh Barty.

Ninth-seeded Daria Gavrilova of Australia survived a tough challenge to beat Katerina Siniakova of the Czech Republic 7-5, 2-6, 6-4.