Serena Williams continues rankings climb

Kim Clijsters and Maria Sharapova saw their world tennis rankings slip this week while Serena Williams continued her climb up the list. Clijsters retired during her second-round match last week at the Rogers Cup where she had been the defending champion. The resulting loss in rankings points allowed Vera Zvonareva to move by her for the No. 2 spot in the rankings. Clijsters defeated Sharapova in the 2010 Rogers Cup final and Sharapova went out in the quarterfinals this year, which allowed two women to pass her in the rankings and drop her from fifth to seventh. Clijsters and Sharapova also met in last year's finals in Cincinnati, which is the WTA stop this week. Clijsters isn't in the Cincinnati draw. Sharapova is seeded fifth. Williams is 15-2 since returning from a nearly yearlong layoff due to injuries. She's won her last 11 matches and took the title Sunday at the Rogers Cup. That pushed her to No. 31 in the rankings, up from 80th. She is in the field at Cincinnati. Caroline Wozniacki remains ranked No. 1. She's held the spot for the last 27 weeks and 45 weeks in her career. She has 9,915 rankings points. Zvonareva has 7,045 points and the third-ranked Clijsters, with 6,726, could sag further in the coming weeks if injuries continue to keep her off the court. Victoria Azarenka (6,390) is fourth and Li Na (5,671) is up one place this week to fifth. Petra Kvitova (5,561) has reached a career-high No. 6 ranking ahead of Sharapova (5,446). Francesca Schiavone (4,955) and Marion Bartoli (4,325) keep the Nos. 8 and 9 rankings, respectively. Samantha Stosur, the Roger Cup runner-up, returns to the Top 10 with 3,775 points, pushing Andrea Petkovic (3,530) down one place to 11th.