Petra Kvitova’s hopes of defending her Wimbledon title were shot to pieces in a hail of Centre Court cannon fire from Serena Williams who ousted the defending champion 6-3 7-5 in their quarterfinal Tuesday. The quality of tennis on show could have graced the final as both players tore into each other with rasping serves and ferocious groundstrokes, but it was the greater power and fight of the four-times winner that won out. “I had to step it up today because I was playing the defending champion,” Williams said in a courtside interview. “It was tough. But I had absolutely nothing to lose. It was really fun. I’m having the time of my life out here, and I’m enjoying every moment. “It’s exciting. Everyone thinks about lifting the trophy. It’s something I’ve thought about, but my main goal is to keep progressing. If I want to win the title, I have to step it up. There are a lot of people vying for it. I’m happy just to be in the tournament.” Both players came on court with a look of cold-steel concentration etched into their faces and the tennis on show in the opening set was arguably the highest quality witnessed in the women’s competition this year. It had looked very even in the early games before Williams turned up the heat with a vicious display of power hitting that left Kvitova stammering for a response. Any return that dropped midcourt was sent crashing past the Czech with fearsome regularity. Williams broke in the sixth game of the first set when Kvitova sent a crosscourt forehand wide and then closed it out when the Czech sent a backhand return long. The second set was more nip and tuck, with Kvitova hanging tough and creating a set point in the 10th game. After saving that, Williams showcased her fighter qualities, firing a put-away straight at her opponent when she had the whole court to aim at. She broke the very next game before serving her 13th ace to bring up match point and closed out with a service winner to set up a semifinal against Belarus’s Victoria Azarenka. Angelique Kerber defeated fellow German Sabine Lisicki, the conqueror of Maria Sharapova, in a nerve-racking battle of the blondes 6-3, 6-7 (7/9), 7-5 to reach her first Wimbledon semifinal. Eighth seed Kerber will face either Polish third seed Agnieszka Radwanska or Maria Kirilenko, the Russian 17th seed, for a place in Saturday’s final after getting the better of big-hitting Lisicki. The match, played under the Centre Court roof as rain continued to plague the schedule, showcased the first time since 1987 that two German women had made the quarterfinals. The 24-year-old Kerber, who had never previously got beyond the third round in four previous appearances at the All England Club, racked up a tour-leading 45th win of the year. But it was a roller-coaster affair for Kerber who squandered four match points as memories of the five match points she wasted in the Eastbourne final against Tamira Paszek almost came back to haunt her. Lisicki, sporting vivid yellow nail polish on her fingers, needed treatment on a painful-looking blister on her left thumb at the end of the first set and quickly fell 3-0 down in the second. But she battled back to 3-3, saved two match points in the 10th game and another in the tiebreak. In the decider, there were six breaks of serve in 11 games before Kerber claimed her fifth win in five meetings against her Fed Cup teammate. Lisicki finished with a whopping 57 winners but 50 unforced errors while Kerber fired down just 19 winners but with a low of 13 errors. Agnieszka Radwanska and Maria Kirilenko suffered frustration on Court One as rain forced their match to be postponed until Wednesday.