Serena Williams has a commanding lead over No. 2 Li Na in the rankings. (Warren Little/Getty Images)
Serena Williams has moved into fifth place for most weeks as the WTA Tour's No. 1 player.
Williams on Monday matched Monica Seles with her 178th week in the top spot. The rankings will remain the same next week in the middle of the BNP Paribas Open.
"Monica was my favorite player. I think she was pretty much everyone's favorite player," Williams told the WTA's website. "I wanted to be like her. I wanted to do everything like her. I even styled my grunt after hers -- I kind of changed it and made it my own. But Monica always inspired me. I've always loved Monica."
Williams, 32, who first ascended to the top spot at age 20 in July 2002, now trails only Steffi Graf (377 weeks), Martina Navratilova (332), Chris Evert (260) and Martina Hingis (209). Serena has occupied the No. 1 ranking since Feb. 18, 2013, when she regained the perch for the first time since 2010 and became the oldest women's No. 1 since the computer rankings were introduced in 1975.
In her last two tournaments, Williams has lost in the fourth round of the Australian Open and the semifinals of the Dubai Championships. Still, she has a 5,865-point lead over second-ranked Li Na.
Williams will not be in the field at the BNP Paribas Open, a tournament she has skipped since 2001, when Serena and her family were booed during the final.
In other rankings news:
• Australian Open finalist Dominika Cibulkova rose from No. 13 to a career-high No. 11 after winning the Mexican Open. She settled in behind an unchanged top 10.
• Christina McHale, a 21-year-old American, jumped 15 spots, to No. 55, after reaching the Mexican Open final.
• Garbine Muguruza, a 20-year-old Spaniard, has cut her ranking in half this year, rising from No. 63 to a career-high No. 32 this week. She inched up four spots after making the final of the Brazil Open, where she couldn't hold a 6-4, 5-2 lead and lost the last 11 games to Klara Zakopalova.