Serena Williams dominates again to reach Rogers Cup semis TORONTO, Aug. 9 (UPI) -- Serena Williams marched into the semifinals of the Rogers Cup Friday with another one-sided victory, her 40th win in 41 matches. Williams ended the eight-match winning streak of Magdalena Rybarikova with a 6-1, 6-1 victory. The top-seeded Williams is seeking her eighth tournament title of the year in 11 events and will try to take another step toward a championship when she meets Agnieszka Radwanska in Saturday's semifinals. Radwanska advanced by downing Sara Errani 7-6 (7-1), 7-5. Williams has played three matches in this week's tour stop and her opponents have won no more than three games in any set. She won almost two-thirds of the points played in the match with Rybarikova, who faced Williams for the first time in her career. Rybarikova was coming off a tournament title last week in Washington. Li Na will meet Sorana Cirstea in the other semifinal match. Li defeated Dominika Cibulkova 7-6 (7-1), 6-2 and Cirstea fought off defending champion Petra Kvitova 4-6, 7-5, 6-2.