World number one Lee Chong Wei was forced to fight for his place in the world championships Wednesday in a thrilling battle with an unseeded opponent.
The crowd in Guangzhou were left stunned as they watched the Malaysian star lose the first game 14-21 to Dionysius Hayom Rumbaka of Indonesia, who is ranked 26th in the world.
Rumbaka has met Lee five times and never beaten him, but he showed no sign of nerves, repeatedly forcing him to the net with drop shots which took the pace out of the Malaysian's game.
Lee looked increasingly rattled and murmurs of disbelief rippled around the Tianhe gymnasium, as he went behind in the second game.
The pair traded smashes and body shots, but Lee recovered to take the second game 21-18 before winning the third 21-11, hitting his attacking stride in the final points.
Lee, 30, is gunning for Malaysia's first ever world title, off the back of wins this year in South Korea, Indonesia, India and Malaysia with fans hoping for another classic final between him and Chinese superstar Lin Dan.
Olympic and world champion Lin, who has spent most of this year on the sidelines of the sport to spend time with his family, plays his second-round match later Wednesday.
Number two seed Chen Long of China was also given a run for his money by Japanese veteran Sho Sasaki, winning 21-15, 21-12 after a lacklustre start which saw him go 6-10 down in the first game.
Reigning All-England champion Chen showed his strength in the second, delivering blistering smashes of up to 242 kilometres per hour (150 miles).
Chen is on course to meet China's Lin in the quarter-finals if both survive their third-round matches.
Top-ranked women's singles seed Li Xuerui of China, who took gold at the London Olympics, strolled to victory in her first game of the tournament, beating Ukraine's Marija Ulitina 21-9, 21-10.
Chinese women's doubles pair Ma Jin and Tang Jinhua, ranked second in the world, won 21-5, 21-5 against Australia's Jacqueline Guan and Gronya Somerville.