Top seeds Chen Hong and Wang Chen crash out of world championships

China's Chen Hong and Wang Chen of Hong Kong, the two top singles seeds, both went out in the quarter-finals on a day of shocks in the world championships in Birmingham on Friday.

By far the bigger of them was the demise of Chen, a winner of the All-England title last year, who held a match point for a straight games win and was beaten 5-15, 17-14, 15-9 by Shon Seung-Mo, the 13th seeded South Korean.

Even more surprisingly the 23-year-old from Kyungnam did it despite needing extensive icing on an injured left knee during the five minute interval between the second and third games.

He now plays the ninth seeded Commonwealth champion from Malaysia Wong Choon Hann.

Earlier Zhou Mi, the fifth seeded All-England champion from China, caused the women's singles upset by beating Wang Chen 11-6, 5-11, 11-4.

"Even though I lost, it's still been good for me," Wang said.

"I feel I have improved and that I am getting closer and closer. But I won't regard myself as world number one until I have beaten the Chinese players," she added.