Caroline Garcia produced a stunning recovery from a first-set bagel against Caroline Wozniacki to keep her hopes of a semi-final place at the WTA Finals alive.
Wozniacki had been the standout player in Singapore with comprehensive victories over Elina Svitolina and Simona Halep, but making it three out of three proved too much.
It looked like she would race to victory after dominating the opening set on Friday, but Garcia dug deep and gave herself the chance of a last-four spot with a 0-6 6-3 7-5 win.
She must now wait for Svitolina's clash with Halep to know her fate, the world number eight needing a victory for the former to secure her progress.
After brushing Halep aside on Wednesday, Wozniacki quickly picked up where she left off as Garcia struggled to find any momentum - the Dane's flat groundstrokes forcing errors from the other side of the net.
To add to Garcia's frustrations, Wozniacki was unerringly accurate when presented with passing shots of her own, the world number six racing into a 1-0 lead after just 22 minutes.
The first set also saw the continuation of an improved serving record for Wozniacki, who only dropped two points to her French rival.
A crisp forehand passing shot secured the opening set, and her march towards victory seemed to continue at the start of the second.
However, after winning the opening seven games of the match, Wozniacki encountered her first bump in the road in Singapore as Garcia found a new gear.
The world number eight upped her tempo and finally applied pressure on her opponent, and she reaped the rewards as chinks in Wozniacki's armour began to show.
She was broken three times in the closing stages of the set as Garcia levelled things up, giving her the momentum and a chance of making the semis.
Back came Wozniacki with an early break but Garcia was in no mood to lie down and stayed in the match with some superb returning - particularly on the backhand side.
Wozniacki was still able to open up a 5-3 lead and served for the match, but she could not see off Garcia and minutes later she was battling to stay in the contest.
She saved the first match point that Garcia had fashioned but when the pressure was applied again it was too much for the Dane - leaving the victor celebrating an unlikely win.
Garcia  bt Wozniacki  0-6 6-3 7-5
Garcia - 31/33
Wozniacki - 20/21
Garcia - 1/2
Wozniacki - 8/6
BREAK POINTS WON
Garcia - 5/13
Wozniacki - 5/9
FIRST SERVE PERCENTAGE
Garcia - 76
Wozniacki - 58
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Garcia - 58/41
Wozniacki - 65/42
Garcia - 87
Wozniacki - 93