Third seed Chetan Anand staved off an early scare from Chong Chieh Lok of Malaysia to enter the second round of the Indian Open Grand Prix badminton tournament in Hyderabad on Wednesday.

The Indian shuttler rallied strongly after losing the first game to emerge a 14-21, 21-9, 22-20 winner after 47 minutes.

China's Long Chen pulled off probably the biggest upset of the tournament when he stunned world No 1 Lee Chong Wei of Malaysia 21-7, 16-21, 18-21.

Anand and Lok ran neck and neck in the decider -- the scores reading 14-14, 16-16, 19-19 and 20-20 -- before the world No 12 Indian sealed the match at 22-20.

The victory set up a second round clash with another China's Wenlong Zhou later in the evening.

World No 1 Lee Chong caved in after an impressive start. He whipped Long 21-7 in first game, but world number 147 Long took the second game 21-16.

In the third game, the Malaysian was trailing by five points at 11-16, but put up a spirited fight to reduce the deficit to 12-18, 16-18 before leveling the score at 18-18.

However, the Chinese had the last laugh as he kept his cool to take the next few points and clinch the affair at 21-18.

Anup Sridhar, seeded 13, had things his way, spanking compatriot Sachin Kumar Rana 21-3, 21-7 in just 13 minutes.

Anand said it was good to have a tough clash at the start of the tournament.

"It is good to have a tough first round match as winning it makes me charged up and more confident and gives me a good momentum to go for the kill in the next matches," he said.

"There was drift from one side and it was difficult to control the shuttle and keep it down. There were side movements and I was finding it difficult to play my stokes, so I took some time to find my rhythm. But once I was in third game I made sure he (Lok) did not go away with the match," the world number 12 added.