Caroline Wozniacki is out of the ASB Classic.
The former World No1 lost 6-1 3-6 4-6 to 2016 finalist Julia Goerges, who completed one of the best comebacks in the history of the tournament.
Goerges looked down and out halfway through the match and was three games from elimination in the second set before a dramatic turnaround.
The German had only won one of the first 10 games and was struggling on serve, with six double faults.
But the world #53 reeled off six successive games to seal the second set, as a bemused Wozniacki called for her coach.
The positive trend continues in the third set for Goerges, as she sprinted to a 5-1 lead.
However, that was the cue for Wozniacki to launch her own great escape, as she broke the German and held twice.
Goerges had started to wobble but showed enough composure to serve out the match, finishing in style with an with an ace.
"I just tried to hang in there somehow," explained Goerges after the match. "I missed everything that I could miss and she didn't miss one ball. I just said [to myself] I have to fight and stay in it and somehow find a way to turn this match around. I simply love this court so I wanted to spend a bit more time here."
8:40pm Julia Goerges could be about to cause yet another upset at the ASB Classic.
The German is ahead 4-1 in the final set against World No19 Caroline Wozniacki, and is playing some great tennis.
It's been an astonishing turn around. Goerges dropped the first set 6-1 and was down 3-0 in the second set, as she struggled for touch and had made six double faults.
But the 2016 finalist found something to win six consecutive games and take the second set 6-3.
5.00pm: Promising Japenese teenager Naomi Osaka has joined the mounting casualty list at the ASB Classic, withdrawing injured from her quarter-final match-up with Croatian Ana Konjuh.
The clash was expected to be a highlight of the tournament's third day, showcasing two of the WTA circuit's rising stars, but Osaka lasted just 13 minutes and two games, losing both, before bowing out with a wrist injury.
She had earlier progressed through the second round without lifting a racquet, after superstar Venus Williams also defaulted through injury.
Konjuh now faces the winner of Caroline Wozniacki-Julia Goerges in tomorrow's semi-finals.
4.25pm: Jelena Ostapenko is through to the ASB Classic semi-finals.
The 19-year-old Latvian dispatched American Madison Brengle 7-5 6-3 in an entertaining quarter-final.
Brengle, who famously beat Serena Williams in a huge upset yesterday, couldn't reach the same heights today.
The American took an early 3-0 lead in the first set, as the world No.44 Ostapenko struggled to find her range.
But Ostapenko, who is one of only six teenagers in the top 100, was too powerful for Brengle from the baseline and also displayed some great touches at the net.
The Latvian dominated in the second set. She only had a 52% first-serve percentage in the second set, but returned superbly to constantly put the Brengle serve under pressure.
She converted her third match point to seal the match in just under 90 minutes.
3.35pm: Jelena Ostapenko has taken the first set 7-5 in her quarter-final against American Madison Brengle.
Brengle, who stunned the tennis world yesterday by sending Serena Williams out of the tournament, started well on her return to centrecourt this afternoon.
She took an early 3-0 lead, as the Latvian struggled to find her range, while Brengle was rock solid from the baseline.
But Ostapenko, who beat local hope Marina Erakovic in the first round, won five successive games to take the initiative.
The tenacious Brengle found another break to level at 5-5, but Ostapenko raised her game again to seal the set in 46 minutes.
2.30pm: The seeds have continued to tumble at the ASB Classic, with fourth seed Barbora Strycova dumped out of the quarterfinals by little-known American Lauren Davis.
Davis, ranked 61 in the word, cruised to a 6-1 win in the first set, but encountered more resistance from the Czech player in the second, taking out the match in a tiebreak.
Leading the second set 5-4, Davis had the opportunity to serve for the match and was within just two points of victory, before a string of unforced errors opened the door for Strycova.
Davis recovered to win her next service game and send the set to a tiebreak, which was decided by an unforced error from Strycova.
It will be Davis' second semifinal appearance in Auckland, having made it through to the final four in the 2015 tournament.
The result leaves just one of the top four seeds - Caroline Wozniacki - alive at the tournament following the premature departure of the Williams sisters yesterday.
1.20pm: World number 61 Lauren Davis has cruised to a shock 6-1 win in the opening set of her quarter-final over fourth seed Barbora Strycova.
Davis, one of the shortest players on the tour at 1.57m, troubled Strycova early on with her speed and agility, with the 23-year-old willing to chase down everything.
The young American failed to advance out of qualifying last year, but made the semi-finals of the Auckland tournament in 2015.
1.05pm: It's quarterfinals day at the ASB Classic and after the dramas of the opening few days, it is looking like the weather will play ball.
Up on centrecourt now is fourth seed Barbora Strycova, who has been elevated to one of the new favourites for the title, alongside Caroline Wozniacki, following the shock departure of the Williams sisters yesterday. Strycova is taking on American Lauren Davis.
The match of the day is expected to be the showdown between teenage stars Ana Konjuh of Croatia and Japan's Naomi Osaka. Just one ranking spot separates the two teens, who are part of the WTA's Next Generation programme and are seen as the faceS of women's tennis in years to come.
In the other quarter-final match-ups, Madison Brengle - the player who sent Serena Williams packing yesterday - will take on Latvia's Jelena Ostapenko, while Wozniacki will meet Germany's Julia Goerges in the late game.