Thailand, who have one of the youngest squads in the competition, didn’t show any respect to their more established opponents to carve out a 3-1 victory.
China, who have yet to drop a point in the tournament, crushed Germany 3-0 while in other quarter-final ties, defending champions South Korea had to dig deep before beating Taipei 3-2 and Japan (right), edged Indonesia by the same margin.
Reigning European champion Tine Baun had given Denmark a flying start when she defeated three-time world junior champion 17-year-old Inthanon Ratchanok 21-18, 21-12.
However, that was as far as the Danes got as the Thais secured two critical points over their European counterparts. 20-year-old Porntip Buranaprasertsuk levelled the tie by beating Karina Jorgensen 18-21, 21-18, 21-12 before Sapsiree Taerattanachai, also 20 years of age, put the Thais 2-1 up by outlasting Danish talented youngster Line Kjaersfeldt 21-19, 13-21, 21-18.
Thailand then clinched victory when their scratch pair of veterans Saralee Thoungthongkam-Kunchala Voravichitchaikul (left), proved too powerful for Marie Roepke-Line Damkjaer Kruse, romping home 21-15, 21-17 to seal victory.
South Korea, meanwhile, had to comeback from a 2-1 deficit to beat Taipei, who like Thailand, have several youngsters in their team.
Hwang Hye Youn was Korea’s match winner as she took 48 minutes to beat Hung Shih Han 21-18, 25-23 to clinch the winning point after a gruelling contest.
The Koreans had gone ahead when Sung Ji Hyun edged teen titan Tai Tzu Ying 18-21, 25-23, 21-10.
Taipei won the next two points via Cheng Wen Hsing-Chien Yu Chin and Pai Hsiao Ma, who defeated Kim Min Jung-Ha Jung Eun and Bae Youn Joo respectively.
Kim Ha Na-Jung Kyung Eun levelled by beating Wang Pei Rong-Hsieh Pei Chen to set up a thrilling finale which went their way due to Hye Youn’s delicate touches.
Waiting for them in the semis will be Japan, who had Minatsu Mitani to thank for clinching a 3-2 victory over Indonesia following her 19-21, 21-13, 21-17 victory over Lindaweni Fanetri.
Fo full results, click here.