Serena Williams has set the record for single-season prize money in women's tennis by topping $6.5 million in 2009.
Williams broke the WTA mark of slightly under $5.5 million, earned by Justine Henin in 2007.
The American won the season-ending tour championships on Sunday, beating older sister Venus in the final, and ends the year ranked No 1. The younger Williams also won the Australian Open and Wimbledon in 2009.
Williams' career prize money is now at a record $28.5 million.