
The second-seeded Williams, who also won this Grand Slam event in 2003, '05 and '07, will replace Serbia's Jelena Jankovic as the No. 1 ranked player in the world come Monday.
The four Australian Open titles are tied for the most-ever in the open era as Williams joined Margaret Court, Evonne Goolagong-Cawley, Steffi Graf and Monica Seles on that list.
The Saturday victory for Williams, which came in just 59 minutes, occurred just a day after she and sister Venus took home the women's doubles title.