Angelique Kerber Likely to Move up to World No. 2 on WTA Tour Rankings

Angelique Kerber's upset victory over Serena Williams in the Australian Open final on Saturday is expected to see her move from sixth to second on the WTA Tour rankings. (Kerber Stuns Serena Williams to Win Maiden Grand Slam)

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. (German Stars Delight in Kerber's Australian Open Win)

Kerber 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. (Williams Hits Back at Critics After Shock Australian Open Loss to Kerber)

Williams was an overwhelming favourite at the Australian Open, where she had won all six previous times she'd reached the final, and was trying to equal Steffi Graf's Open-era record of 22 Grand Slam singles titles.

For the second time in as many majors, though, she fell short. Williams won the Australian Open, French Open and Wimbledon titles in 2015 before losing to Roberta Vinci in the US Open semifinals.

The 34-year-old Williams hadn't lost a set in the first six rounds here until dropping the first on Saturday night against No. 7-seeded Kerber, who was playing in her first Grand Slam final.

Meanwhile, 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.

Safarova did not play in Melbourne due to a bacterial infection.