Seventeen-year-old South Korean schoolgirl An Se-Young stunned Taiwan's world number one Tai Tzu-ying to burnish her fast-growing reputation.
Rising star An, who is ranked 50th in the world, roared back to defeat Tai 14-21, 21-18, 21-16 in 66 thrilling minutes.
Taiwan and title-holders South Korea were already into the quarter-finals of the mixed-team world championships, but this was further evidence of An's precious talent.
The teenager An, who also won the New Zealand Open said: "My strategy was to defend in the beginning of each rally and then to take my opportunity.
"My coach advised me to pay attention to the front and keep the rally going.
"I'm surprised I could beat her."
The 24-year-old Tai said that she had a niggling injury but did not use that as an excuse.
"She's tall, powerful and has very good footwork," the Taiwanese said of her young opponent, who only turned 17 in February.
"She's good in all aspects of the game. She will be an outstanding player in future for sure."