But she is close on their heels and, having being knocked out early at last year's Australian Open, is well placed to pick up big ranking points in Melbourne later this month.
Azarenka, who will be top seed at the year's first Grand Slam, has 10,595 points, 450 points ahead of Sharapova and 845 points clear of Williams.
WTA top rankings
1. Victoria Azarenka (BLR) 10,595 pts2. Maria Sharapova (RUS) 10,0453. Serena Williams (USA) 97504. Agnieszka Radwanska (POL) 75055. Angelique Kerber (GER) 55506. Li Na (CHN) 52557. Sara Errani (ITA) 51008. Petra Kvitova (CZE) 50859. Samantha Stosur (AUS) 413510. Caroline Wozniacki (DEN) 376511. Marion Bartoli (FRA) 374012. Nadia Petrova (RUS) 304013. Ana Ivanovic (SRB) 284114. Maria Kirilenko (RUS) 254015. Dominika Cibulkova (SVK) 249516. Roberta Vinci (ITA) 247517. Lucie Safarova (CZE) 212518. Julia Goerges (GER) 196519. Ekaterina Makarova (RUS) 184120. Yanina Wickmayer (BEL) 1840