Dane’s defeat means the tournament’s three biggest drawcards are all eliminated.
The ASB Classic's greatest line-up in history has turned into the greatest flop as Caroline Wozniacki - the only player with genuine star power remaining in the tournament - crashed out of last night's quarter-finals.
Wozniacki was felled by world No53 Julia Goerges, who recovered from a horror start, in which she won just one of the first 10 games, to record a 1-6, 6-3, 6-4 win.
Organisers had been pinning their hopes that Wozniacki, the tournament's third seed, would go deep into the tournament following the early departure of the Williams sisters, the event's headline acts, on Wednesday. The Danish star was the sixth of the top eight seeds to bow out before the semifinals, with only Latvian Jelena Ostapenko (7) and Croatian Ana Konjuh (8) still in the hunt for the title.
Goerges, runner-up to Sloane Stephens in Auckland last year, will meet Konjuh in one semifinal today, while Ostapenko will take on American Lauren Davis in the other.
Wozniacki made quick work of the opening set, cleaning up Goerges in just 23 minutes as the German struggled with her ball placement.
It looked as though the second set was headed much the same way. The former world No 1 took a 3-0 lead and was on track to wrap up the match before the entrees had even been served in the corporate boxes. But a brutal half volley from Goerges kickstarted a stunning swing in form.
Shots that Goerges had been spraying wide in the first 10 games were suddenly finding their mark, as she rattled off six straight games to claim the second set.
"I think the conditions got a little faster at one point as it got cooler and [Goerges] just started hitting everything and all of a sudden it was going in," a shell-shocked Wozniacki said.
The momentum stayed with the German early in the third as she raced away to a 5-1 lead, before Wozniacki produced some late resistance. But on her second opportunity to serve for the match, Goerges did not falter, securing the win with a brilliant ace down the line - her ninth of the night.
Goerges struggled to explain the remarkable turnaround.
"[I went] from the worst to the best," she said. "It was a very strange match for me at the beginning because I didn't have any rhythm at all. I just really struggled with the shadows and the sun and I really had no feeling for the ball."
Last night's match was almost a microcosm of Goerges' career, with the veteran having been plagued by inconsistency. She reached a career high ranking of 15 in 2012, but has since languished around 50-70.
Wozniacki said Goerges possesses the game to challenge a lot of the top players on the circuit.
"When she's on, she's on. You saw out there she was serving aces everywhere and all I could do was be a goalkeeper and try to get it back."
Goerges is a regular visitor to Auckland, with this her seventh appearance at the tournament. She has had mixed results, with this year just the third time she has made the final four.
Auckland has also proven a boom or bust venue for Davis. This year appears very much a boom year. The world No 61 advanced through to the final four with a shock 6-1, 7-6 (4) win over fourth seed Barbora Strycova. It will be Davis' second semifinal in Auckland, having advanced to the final four in 2015, where her giant-beating run was ended by eventual champion Venus Williams.