A pumped up Dominika Cibulkova kept her hopes of qualifying for the WTA Finals last four alive and dumped Simona Halep out with a straight-sets victory in Singapore on Thursday.
Cibulkova had to win her final Red Group match in two sets in order to have any chance of making it through and a 6-3 7-6 (7-5) kept the tournament debutant in the hunt.
Halep, playing with heavy strapping on her left knee, would have advanced with a win in her last round-robin match, but the third seed's season was ended by the impressive Cibulkova.
Angelique Kerber is guaranteed a semi-final spot ahead of her clash with Madison Keys later in the day and Cibulkova will also go through if the world number one beats the American in straight sets.
Seventh seed Cibulkova was a woman on a mission with no margin for error, breaking Halep to love in the second game of the match and winning 12 points in a row to keep the world number four at bay.
Cibulkova, who lost her first two matches, prowled around the court, showing great intensity and controlled aggression and did not face a solitary break point as she unleashed some fierce winners to take the opening set - which put Kerber through.
Halep was clearly troubled by her knee, but stood up to a Cibulkova barrage, coming from a break down in the second set three times to take an absorbing contest to a tie-break.
Cibulkova ended Halep's resistance - and her season - with two mini-breaks to stay in contention, gaining her rewards for such a positive display under pressure.
Cibulkova  bt Halep  6-3 7-6 (7-5)
Cibulkova - 32/27
Halep - 10/13
Cibulkova - 0
Halep - 1
BREAK POINTS WON
Cibulkova - 4/11
Halep - 3/6
FIRST SERVE PERCENTAGE
Cibulkova - 70
Halep - 66
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Cibulkova - 79/32
Halep - 59/44
Cibulkova - 82
Halep - 66