LONDON, July 3: Four-time Wimbledon winner Serena Williams reached the semifinals at the All England Club on Tuesday with a 6-3, 7-5 defeat of defending champion Petra Kvitova.

The US sixth seed brought all her experience to bear as she punished the Czech title-holder for missing a chance to take the second set.

The 30-year-old came through her quarterfinal in an hour and 24 minutes under the Centre Court roof.

She faces either Australian Open champion Victoria Azarenka, the Belarusian second seed, or in-form unseeded Austrian Tamira Paszek in the semis.

"She's been playing so well on grass, hasn't lost since last year, so that was tough," Williams said of Kvitova."I have absolutely nothing to lose so it's really fun. I'm having the time of my life out here and enjoying every moment. It's exciting.”

However, Serena knows she will have to step up another gear in the semifinals.

"I'm going to have to if I want to win the title. There's a lot of people vying for it still," she added.

She said a fifth Wimbledon singles title was "definitely something that I've thought about."

It is only the second time she has reached a Grand Slam semi-final since winning the 2010 Wimbledon title.

Williams had won her previous two encounters with Kvitova, both in 2010, knocking the 22-year-old left-hander out of the Australian Open second round and the Wimbledon semi-finals.

The pair were the only two champions left in the draw after the first round exit of Serena's sister Venus, and world number one Maria Sharapova in the last 16. Williams fired 23 aces -- a Wimbledon women's singles record -- to make it into the last 16 and was raining down booming serves against Kvitova, winning 86 percent of points on her first serve. Agencies