The WTA has announced that Serena Williams is guaranteed to finish the year as the world No. 1 player for the third time.
This season she has lost only four singles so far.
Williams, who also finished the year on top in 2002 and 2009, has won nine WTA titles this season including the French Open and U.S. Open.
The 32-year-old Williams returned to the No. 1 spot in February, when she became the oldest player to top the rankings.
She is the seventh player to finish at least three seasons at No. 1, alongside Steffi Graf (eight times), Martina Navratilova (seven times), Chris Evert (five times), Lindsay Davenport (four times), Justine Henin (three times) and Martina Hingis (three times).