Daniela sorry for winning.

DANIELA Hantuchova apologised to her doubles partner after knocking her out of the women's singles.

Hantuchova, unseeded at Wimbledon for the first time since 2004, came from a break down in the first set to gain a 6-4 6-3 victory over Ai Sugiyama, of Japan.

"It's never a nice feeling having to play Sugi because she's one of my best friends," Hantuchova said. "We've got such a great history so I said sorry after the match." Hantuchova, of Slovakia, has struggled with flu but will have the weekend to recover for her fourthround match against Serena Williams, against whom she has already lost twice at Wimbledon.

Williams beat Italy's Roberta Vinci 6-3 6-4 while fourth seed Elena Dementieva needed only 59 minutes to book her place in the last 16 by thrashing fellow Russian Regina Kulikova 6-1 6-2.

Dementieva's next opponent will be another Russian, Elena Vesnina, who gained a 7-5 4-6 6-4 win over 14th seed Dominika Cibulkova, of Slovakia.

Tenth seed Nadia Petrova came from a set and a break down for a third successive win, over Argentina's Gisela Dulko, second-round conqueror of Maria Sharapova.

Petrova converted only three of 14 break points but prevailed 3-6 6-3 6-4 to earn a meeting with eighth seed Victoria Azarenka, of Belarus, who gained a 7-5 6-3 victory over Romania's Sorana Cirstea. France's Virginie Razzano saw seventh seed rival Vera Zvonareva pull out with an ankle injury..