Williams into last eight in Madrid

Serena Williams admitted she started badly against Caroline Wozniacki before eventually claiming a Madrid Open last-eight place.

The ninth-seeded American came from a set down to win 1-6 6-3 6-2 in Spain and conceded afterwards she was not at the races in the opening set. Williams, who was broken three times in the first set by Dane Wozniacki, looked in real trouble early on but responded with four breaks of her own over the next two sets to claim the hard-fought win. Afterwards, Williams admitted she had begun slowly but was pleased to finally prevail and is now through to the quarter-final, where she faces second seed Maria Sharapova. "I had a slow start today, I don't know why," said the 30-year-old. "I was sluggish and mentally maybe fighting some demons. "I started trying to play better, the first set was not me at all. I knew I had to get better. I just tried to play my game." Fourth seed Agnieszka Radwanska is also through to the last eight after she saw off Roberta Vinci 7-6 (7/1) 6-4, while qualifier Lucie Hradecka, who shocked third seed Petra Kvitova on Wednesday, continued her fine form with a 6-2 7-6 (7/5) win over Ekaterina Makarova.