Williams dethrones Kvitova, Azarenka marches on
Serena Williams produced a champion's display to knock out title-holder Petra Kvitova on Tuesday as Victoria Azarenka, Agnieszka Radwanska and Angelique Kerber joined her in the Wimbledon semi-finals.
Kvitova tipped Williams to win a fifth Wimbledon crown after the US sixth seed used her experience and cool nerve to dethrone the Czech with a 6-3, 7-5 victory.
Williams faces Australian Open champion Azarenka in the semi-finals after the Belarusian second seed reached the last four for the second successive year with a 6-3, 7-6 (7/4) win over unseeded Austrian Tamira Paszek.
Meanwhile winning machine Kerber emerged victorious in the all-German quarter-final with Sabine Lisicki after blowing four match points, the eighth seed triumphing 6-3, 6-7 (7/9), 7-5 to notch a tour-leading 45th win of the year.
Kerber faces third seed Radwanska, who became Poland's first Grand Slam semi-finalist in the Open Era.
She defeated Russian 17th seed Maria Kirilenko 7-5, 4-6, 7-5 in a match played across several hours and two courts.
Wimbledon officials decided to break with tradition and move them under the Centre Court roof for the final four games to get the match finished on schedule.
Kvitova, 22, believes Williams will now go on and win the tournament. "I think so," the fourth seed said. "It is very difficult (to beat her). I can't say impossible. She's human.
"That's why she's the great champion, because she knows what she needs to play in the important points. So I think that it's really tough to beat her."
Williams admitted she had needed to step up a gear to get past the big-hitting Czech.
"You can't play a defending Wimbledon champion or Grand Slam champion and not elevate your game. I had to weed out the riff-raff and just get serious," the 30-year-old said.
"I don't know if it was more about dethroning or going out there and playing the match and doing the best that I could."
Azarenka wobbled towards the end of her match but eventually saw off Paszek in a repeat of last year's quarter-final.