LONDON - Russia's Ekaterina Makarova has sent former finalist Agnieszka Radwanska crashing to a surprise exit at Wimbledon, while giant-killer Barbora Zahlavova Strycova claimed another famous scalp.
But the 26-year-old, a quarter-finalist at the Australian and French Opens last year, destroyed the world number four 6-3 6-0 and will play Czech 23rd seed Lucie Safarova for a place in the semi-finals.
Radwanska's exit means three of the top four seeds have been eliminated from the women's draw following the defeats of Williams and Li Na.
Earlier, Zahlavova Strycova moved into the last eight with a 6-2 7-5 victory against former world number one Caroline Wozniacki.
Zahlavova Strycova, the world number 43, had enjoyed the best win of her career in the previous round when she defeated Chinese second seed Li and she added Danish 16th seed Wozniacki to her list of upsets.
The 28-year-old, who served a six-month ban for doping last year, will play compatriot Petra Kvitova for a place in the semi-finals.