Angelique Kerber will finish the year as world number one despite her scratchy recent form.
The German, 28, has enjoyed a phenomenal 2016, winning two grand slams, reaching the Wimbledon final and claiming Olympic silver.
Her rise to top spot after the US Open ended Serena Williams' 186-week reign as world number one.
Kerber was delighted to finish the year as world number one, with Williams to miss the WTA Finals in Singapore due to a shoulder injury.
"It is a great honour and achievement to finish the year as the number one player in the world," Kerber said, via the WTA.
"This is one of the things I've always been dreaming of - to become number one.
"I have worked extremely hard to become the best player I can be and this is a reflection of that effort and the wonderful year I have had."
Kerber is just the second German to hold the top WTA ranking at the end of a year, joining Steffi Graf - who managed it a record eight times.
Her form has dropped off since her success at Flushing Meadows, with early exits in Wuhan and Beijing followed by a run to the quarter-finals in Hong Kong.