Although they won't be official until Monday, the projected rankings show Williams in first, Kerber in second and Simona Halep, the former No. 2 who lost in the first round at Melbourne Park, drop to third.
Agnieszka Radwanska, who lost to Williams in the semifinals, remains in fourth, while Garbine Muguruza drops to fifth from third. No. 5 Maria Sharapova, the 2015 finalist who lost to Williams in the quarterfinals this year, moves to sixth, followed by Flavia Pennetta, Carla Suarez Navarro, two-time Wimbledon champion Petra Kvitova and Lucie Safarova.
Angelique Kerber has upset Serena Williams 6-4 3-6 6-4 to win the Australian Open title, ending the six-time champion's unbeaten streak in finals at Melbourne Park.