Top seed Maria Sharapova was bundled out of the Auckland Classic women's tennis tournament in the quarterfinals on Thursday, beaten in straight sets by unheralded Greta Arn.
The 31-year-old Hungarian, whose best world ranking was 81 in 2002 and is now ranked 88th, dominated the former world number one and three-time Grand Slam winner from the start to win 6-2, 7-5.
Sharapova is currently ranked 18th as she rebuilds following shoulder surgery, and had earmarked the tournament as crucial to her preparation for the Australian Open and as part of her bid to regain the world top spot.
But she made too many unforced errors, starting when she dropped her serve in the opening game, and was philosophical about her shock loss.
"But that's the way it goes. You look forward to the next one. That's the good thing about tennis," she said. "Just because I lost doesn't take anything away from the tournament for me."
Arn was ecstatic. Before the match she described playing Sharapova as "a dream come true" and afterwards said she was stunned by the outcome.
Sharapova was the biggest name she has beaten and "I don't know what to say. I am like a little girl. My dream has come true."
Arn broke Sharapova twice to race through the first set in 30 minutes and then after trailing 2-4 in the second set she broke twice again before holding her own serve to take the match.
She will play fourth-seed Julia Goerges in the semi-finals after the German dropped the first set of her quarter-final against wildcard Kateryna Bondarenko from Ukraine before recovering to win 5-7, 6-2, 6-2.
Defending champion Yanina Wickmayer was under no pressure as she coasted into the semi-finals with a 6-0, 6-2 win over Romania's Simona Halep to set up a semi-final against China's Peng Shuai, who beat British qualifier Heather Watson 6-4, 7-5.