China's Zheng Jie reacts during her women's singles, third round match against Ana Ivanovic of Serbia yesterday. - AP

WIMBLEDON, England (AP):

Top-seeded Ana Ivanovic was knocked out in the third round of Wimbledon yesterday by 133rd-ranked Zheng Jie of China, extending a spate of stunning upsets at the All England Club. The player, who took over the number one ranking after winning the French Open earlier this month, slumped to a 6-1, 6-4 loss to the wild card entry and doubles specialist.

"It's a surprise for me," said the 24-year-old Zheng, who won the Wimbledon doubles title in 2006. "Thanks to Wimbledon, (which) gave me a wild card. I just tried my best and had to keep going, going."

Ivanovic went out a day after 2004 champion and third-seeded Maria Sharapova was ousted by 154th-ranked Alla Kudryavtseva and two-time men's runner-up Andy Roddick was bounced by Janko Tipsarevic. A day earlier, Australian Open champion and number three-ranked Novak Djokovic fell to Marat Safin.

Other title favourites fared better yesterday.

Roger Federer continued his march toward a sixth straight Wimbledon title by beating 53rd-ranked Frenchman Marc Gicquel 6-3, 6-3, 6-1 on Centre Court for his 62nd consecutive win on grass and 37th straight at the All England Club. His next opponent will be Lleyton Hewitt, who won Wimbledon in 2002 - the year before the Swiss star won the first of his five straight titles.

Two-time women's champion Serena Williams dispatched 2006 winner Amelie Mauresmo 7-6 (5), 6-1, extending her supremacy over the Frenchwoman to a career record of 10-2.

Fifth-seeded David Ferrer was ousted by Croatia's Mario Ancic 6-4, 6-4, 6-7 (5), 7-6 (3) in a match that ended on Centre Court in near darkness around 9:15 p.m. Ancic is the last player to have defeated Federer at Wimbledon - he did it as a qualifier in the first round in 2002. Ferrer's exit means six of the top 10 seeded players in the men's draw have gone out so far in the first three rounds.