World number one Chen Long suffered a shock defeat in the second round of the All England Open on Thursday, going down in straight games to unseeded Chinese compatriot Xue Song.
With Lee Chong Wei also losing on Wednesday, the tournament has now lost both of its top seeds in the men’s draw.
Xue edged two tight games against his much-higher ranked opponent, winning 42 points to Chen’s 36 on the way to a 21-19, 21-17 victory in 49 minutes.
Xue moves on to face sixth seed Viktor Axelsen, after the Dane defeated Son Wan Ho 21-19, 22-24, 21-12.
Axelsen’s countryman Jan O Jorgensen is now the top seed remaining after he beat Ng Ka Long Angus 21-13, 21-16.
Awaiting him in the quarter-finals is fifth seed Lin Dan, who was a 20-22, 21-6, 21-8 winner over Sho Sasaki.
Others to reach the last eight included fourth seed Kento Motota and eighth seed Tian Houwei.
The top four seeds in the women’s draw, meanwhile, all advanced safely.
Spaniard Carolina Marin made light work of Maria Febe Kusumastuti, winning 21-17, 21-7 in just 35 minutes.
Second seed Saina Nehwal of India ousted Busanan Ongbumrungphan 21-16, 21-9, while third seed Li Xuerui edged Porntip Buranaprasertsuk 27-25, 21-13.
China’s Wang Yihan, the fourth seed, advanced with a 21-18, 23-21 victory over He Bingjiao.
South Korean fifth seed Sung Ji Hyun was eliminated, however, going down 21-13, 23-21 to Tai Tzu Ying.