Belarussian Azarenka has 10 190 points, while Maria Sharapova of Russia stays second on 9 115 and Serena Williams of the United States remains third on 7 900 going into this week's season-ending WTA Championships in Istanbul.
Kerber improves to fifth place, while Errani is up to seventh.
WTA top 10 as of October 22 (previous ranking in parenthesis):
1. (1) Victoria Azarenka, Belarus, 10 190 points
2. (2) Maria Sharapova, Russia, 9 115
3. (3) Serena Williams, United States, 7 900
4. (4) Agnieszka Radwanska, Poland, 7 095
5. (6) Angelique Kerber, Germany, 5 470
6 (5) Petra Kvitova, Czech Republic, 5 215
7. (8) Sara Errani, Italy, 4 855
8. (7) Li Na, China, 4 726
9. (9) Samantha Stosur, Australia, 4 120 10. (10) Marion Bartoli, France, 3 740