Since I didn't do the youngest, I figure I'll do the oldest
Serena Williams will become the oldest world No. 1 in WTA history on Monday after she defeated Petra Kvitova in Doha
Needing to reach the semi-finals of the Qatar Total Open to top the rankings for the first time since October 2010, Williams twice came from behind to claim a 3-6 6-3 7-5 quarter-final victory.
Williams has already spent a total of 123 weeks at the top of the world rankings, a total bettered only by Steffi Graf (377), Martina Navratilova (332), Chris Evert (260), Martina Hingis (209) and Monica Seles (178).
The 15-time Grand Slam champion had the chance to unseat world No. 1 Victoria Azarenka at the Australian Open last month, but suffered a shock quarter-final defeat to Sloane Stephens in Melbourne.
Williams looked to have once again squandered her opportunity when she dropped the opening set in Doha and then went down a break in the decider, but the American dug deep to seal victory.
"It’s awesome,” Williams said. “Since I didn't do the youngest, I figure I'll do the oldest."
Williams will face Maria Sharapova in the last four after the Russian beat Sam Stosur 6-2 6-4 earlier on Friday.