Serena Williams moved with a victory of becoming the oldest top-ranked women's player, sweeping aside Urszula Radwanska 6-0, 6-3 on Thursday to reach the Qatar Open quarterfinals.
If the 31-year-old Serena reaches the semifinals by beating seventh-seeded Petra Kvitova she will return to No. 1 for the first time in 2-and-a-half years. Chris Evert was No.1 in 1985 while just shy of her 31st birthday.
If Serena doesn't make the last four, Australian Open champion Victoria Azarenka can keep the top spot by reaching the final. Third-ranked Maria Sharapova can pass both players if she wins the tournament and Williams and Azarenka lose their next matches.
Serena, a 15-time Grand Slam winner, was joined in the last eight by Azarenka, former No. 1s Caroline Wozniacki and Sharapova, plus 2011 U.S. Open champion Samantha Stosur and Agnieszka Radwanska. Azarenka extended her unbeaten run in 2013 to 11 matches by thrashing Christine McHale of the United States 6-0, 6-0.