Berlin - American Serena Williams retained the lead ahead of Russia's Maria Sharapova in an unchanged top 10 of the women's tennis rankings issued on Monday by the WTA.
Williams has 11 115 points to Sharapova's 10 240, with Victoria Azarenka of Belarus third on 9 325.
WTA top 10 as of April 15 (previous ranking in parenthesis):
1. (1) Serena Williams, United States, 11 115 points
2. (2) Maria Sharapova, Russia, 10 240
3. (3) Victoria Azarenka, Belarus, 9 325
4. (4) Agnieszka Radwanska, Poland, 6 845
5. (5) Li Na, China, 5 880
6. (6) Angelique Kerber, Germany, 5 395
7. (7) Sara Errani, Italy, 5 350
8. (8) Petra Kvitova, Czech Republic, 5 225
9. (9) Samantha Stosur, Australia, 3 790 10. (10) Caroline Wozniacki, Denmark, 3 760