Five-time champion Lin Dan and world No. 1 Chen Long both scored straight-set victories to reach the second round at the badminton All England Open on Wednesday.
Second-seeded Lee Chong Wei of Malaysia, a three-time champion, suffered a surprise defeat to world 37th-ranked Sai Praneeth 24-22, 22-20.
Lee, who missed last year's event due to a doping suspension, rocketed back up the rankings from 182nd to second, but the defeat to the 24-year-old Indian was just beyond everyone's imagination.
Praneeth was promoted to qualification late after teammate and Commonwealth champion Parupalli Kashyap withdrew with an injured knee.
World No. 4 Lin, also a double Olympic champion, beat South Korea's Lee Dong Keun 21-17, 21-17 while Chen Long, the defending champion, took 57 minutes to beat Japanese qualifier Kenta Nishimoto 21-18, 21-12.
Spain's Carolina Marin, the women's world champion and last year's winner here, just held off Bae Yeon Ju of South Korea in an 88-minute encounter.
"The first game was challenging and I'm glad I stayed really calm," said Chen, aiming to win his third All England title in four years.
"I played some matches in the national league but it's very different to playing international matches," added Chen, who was playing his first major tournament this season.
In a titanic battle of the left-handers, Marin, who has broken China's domination to reach world No. 1 with her game of precision skill and passion, made several uncharacteristic mistakes at the net when well set in the rallies against Bae.
She had to save three game points in the opener, failed to finish the match with two match points in the second, and then came from 9-6 down in the decider to win through.
"It's been a long time since my last Superseries event and I've just recovered from a shoulder injury," said Marin after her 25-23, 20-22, 21-15 victory.
Lin, nicknamed Super Dan by Chinese fans, played here for the first time in 2002 and still enjoys the atmosphere of the world's oldest badminton tournament.
"The All-England has so much tradition and I'm excited at what I can do here," he said.
Chen will next meet teammate Xue Song and Lin take on Japan's Sho Sasaki in the second round on Thursday.
