The WTA has confirmed Serena Williams will end 2013 as the number one player in the world.
The American has had another phenomenal season, winning 67 of 71 matches on her way to capturing nine titles, including grand slams at the French Open and US Open.
Williams returned to the top of the world rankings in February - replacing Victoria Azarenka - aged 31, becoming the oldest player to hold the position. She turned 32 on Thursday.
It is the third time she has finished a calendar year on top of the women's game, matching her achievement in 2002 and 2009.
"Serena has proven time and time again throughout her career that she is an incredible champion, both on and off the court," WTA chairman and chief executive Stacey Allaster said.
"This season she continues to rewrite the record books, proving she is one of the sport's greatest athletes of all time."