Australian Open winner Serena Williams replaced Angelique Kerber as world number one in the latest WTA rankings released on Monday.
The American moved up one place courtesy of her victory in Melbourne where she got the better of sister Venus 6-4, 6-4 in the final on Saturday for a record 23rd Grand Slam title.
Kerber's defence of her Australian Open crown ended with a last 16 loss to Coco Vandeweghe with the German now down to second and her American nemesis up 15 rungs to 20th.
Melbourne quarter-finalist Karolina Pliskova climbs two spots to third.
WTA rankings on Monday, January 30:
1. Serena Williams (USA) 7.780 pts (+1)
2. Angelique Kerber (GER) 7.115 (-1)
3. Karolina Pliskova (CZE) 5.270 (+2)
4. Simona Halep (ROM) 5.073
5. Dominika Cibulkova (SVK) 4.985 (+1)
6. Agnieszka Radwanska (POL) 4.915 (-3)
7. Garbine Muguruza (ESP) 4.720
8. Svetlana Kuznetsova (RUS) 3.915 (+2)
10. Johanna Konta (GBR) 3.705 (-1)
11. Venus Williams (USA) 3.530 (+6)
12. Petra Kvitova (CZE) 3.415 (-1)
13. Elina Svitolina (UKR) 2.955
14. Carla Suarez (ESP) 2.625 (-2)
15. Timea Bacsinszky (SUI) 2.347
16. Elena Vesnina (RUS) 2.357 (+2)
17. Barbora Zahlavova Strycova (CZE) 2.295 (-1)
18. Caroline Wozniacki (DEN) 2.295 (+2)
19. Victoria Azarenka (BLR) 2.161 (-5)
20. Coco Vandeweghe (USA) 2.136 (+15)