Azarenka successfully defended her 2012 Australian Open title with a three-set win Saturday over Li Na. The 2012 championship moved Azarenka into the No. 1 spot for the first time. The 2013 win allowed her to keep it. She has been atop the rankings for the last 30 weeks and 49 weeks overall.
But the charge by Williams in the last seven months -- she's lost just two matches and won Wimbledon, Olympic gold, the U.S. Open and the WTA Championships -- along with her advance to the Australian Open quarterfinals has her within 355 points of gaining the No. 1 ranking for a sixth time. She last was No. 1 on Oct. 10, 2010.
Azarenka has 10,325 points to 9,970 for Williams. Maria Sharapova, who lost in the semifinals in Australia, slips to No. 3 this week with 9,545 points.
That was one of three switches affecting the women's Top 10, a relatively small change after a major tournament. Agnieszka Radwanska, whose loss to Li in the quarterfinals was her first of the year, remains fourth with 7,750 points but Li moves from sixth to fifth with 6,255 points, pushing Angelique Kerber (5,695) down one place to No. 6.
Sloane Stephens, the other semifinalist in Melbourne, grabbed attention by beating Williams and throwing a scare into Azarenka. She moves from No. 25 to 17th in the rankings.
Errani, Kvitova and Bartoli are all entered in this week's 21e Open DSF Suez event in Paris where Kvitova is the defending champion. World No. 13 Ana Ivanovic is the top seed for the PTT Pattaya Open in Thailand.