Serena moves into Italian Open semis

Serena Williams reached the semifinals of the Italian Open Friday, advancing after quarterfinal opponent Flavia Pennetta retired, citing a wrist injury. Williams, seeded ninth, was leading at the time -- 4-0 in the first set of the clay-court French Open tuneup. Pennetta, an Italian crowd favorite, said she had injured her right wrist. Williams, who won the event in 2002, will go against eighth-seeded Li Na of China in the semifinals Saturday. Li advanced with a 6-1, 7-6 (7-4) win over Slovak Dominika Cibulkova. Williams, 17-0 on clay this year, won a title in Marid last week, beating top-ranked Victoria Azarenka.