Dominika Cibulkova produced a stunning display to be crowned WTA Finals champion with a straight-sets win over Angelique Kerber.
The Slovakian - who dropped to 66th in the rankings following her first-round exit at this year's Australian Open, which Kerber won - was unplayable at times during Sunday's 6-3 6-4 triumph.
She wowed the crowd with a high-quality showing that left the world number one - who had won each of her previous matches in Singapore, including an opener against Cibulkova - desperately searching for answers she could not find.
Cibulkova was frequently the aggressor, winding up her forehand to devastating effect as she stormed into a 3-0 lead.
An 85 per cent first serve ratio underlined the challenge facing Kerber, who did manage to get back to 3-2, only to surrender another game on serve as Cibulkova continued to find winners from all over the court.
The shot that provided Cibulkova with set point - a glorious passing stroke through the narrowest of gaps - highlighted her confidence as the seventh seed wrapped up the first set in 32 minutes.
Kerber needed to mount a response and was more animated between points, but still found her second serve often punished by her on-song opponent.
A sixth double fault in game seven proved costly as Cibulkova broke to 15, with Kerber's performance a long way short of the one she produced in a 6-2 6-1 semi-final win over defending champion Agnieszka Radwanska.
Cibulkova's last-four match against Svetlana Kuznetsova, in which she lost the first set 6-1, lasted almost twice as long, but she showed no signs of fatigue.
There was, however, evidence of nerves, with Cibulkova spurning three championship points and saving two break points, before finally sealing a memorable victory with a fortuitous ricochet off the net.