Serena wins but Venus loses in Rome

Serena Williams advanced Friday to the semifinals of the Italian Open but her sister Venus was beaten by Maria Sharapova. Serena Williams, seeded ninth, is 17-0 on clay courts this year after she moved into the semifinals. She was up 4-0 in the first set when Flavia Pennetta retired due to a right wrist injury. Sharapova, the world No. 2, defeated Venus Williams 6-4, 6-3, winning nearly two-thirds of the points on serve. She was able to finish off four of her nine break-point chances. Her semifinal opponent Saturday will be 12th-seeded Angelique Kerber, who ousted fourth-seeded Petra Kvitova 7-6 (7-2), 1-6, 6-1. Each player had five breaks but two of Kerber's came in the third set when she didn't face a break point. No. 8-seeded Li Na claimed a 6-1, 7-6 (7-4) decision over 14th-seeded Dominika Cibulkova. Li won 55 percent of points off Cibulkova's first serve and wound up with five breaks. She will go against Serena Williams in the semifinals. Williams is 5-1 lifetime against Li, including having won the last four meetings. Sharapova and Kerber have split their two previous meetings, both of which were this year.