Newly-crowned world number one Angelique Kerber was expected to win the season-ending WTA title. But Dominika Cibulkova pulled off a surprise victory in straight sets.
Slovakia's Dominika Cibulkova pulled off a stunning upset to defeat Germany's Angelique Kerber and win the decider of the WTA Finals, beating the newly crowned world number one 6-3 6-4.
Cibulkova, runner-up in the 2014 Australian Open, turned the tables on Kerber just a week after losing to her in the round-robin stage and captured the biggest title of her career in Singapore.
Kerber went into the final as the overwhelming favourite after taking this year's Australian Open and US Open titles. But the 28-year-old was powerless to stop the Slovakian, who has made an inspired return to the highest level.
Cibulkova was facing an early exit when she lost her first two round-robin matches in Singapore. But she won her last three matches to receive the Billie Jean King trophy and a cheque for just over $2million, making it the most valuable victory of her career.