Saina Nehwal laboured past American Beiwen Zhang in testing three games to reach the women's singles quarter-finals of the All-England badminton championships, here.
The seventh seed Saina defeated the American qualifier 24-22, 18-21, 21-19 in an hour in the second round contest to keep the Indian flag flying in the prestigious championship on Thursday night.
The Indian, who was playing the American for the first time, lost the first game on extra points before pulling off the second. Then at 19-all in a closely-fought third game, Saina held her nerve to take the next two points to edge out her opponent, who in the first round had an easy win over Germany's World No11 Juliane Schenk.
The Commonwealth Games gold medallist next faces fourth seed Chinese Wang Shixian, who brushed aside the challenge of Ireland's Chloe Magee of 21-15, 21-12 in her second round match.
Saina, who is the only Indian left in the championships, said that she was struggling to sleep properly because her room was cold.
World No 10 Pusarla Venkata Sindhu found the going tough on her debut here Wednesday night and lost to Sun Yu of China. Sindhu, who had a 2-1 record against Sun, was beaten in straight games, 21-16, 21-15.
China's top seed Li Xuerui and Ratchanok Intanon of Thailand both dropped their opening games before getting past Minatsu Mitani of Japan and China's Han Li respectively.
In the men's singles, top seed Lee Chong Wei of Malaysia and second-seeded Chinese Chen Long won through their second round matches in straight sets.
Lee eyes Rio
Lee Chong Wei has agreed that to prolong his outstanding career and to reach the Rio Olympics he will have to play substantially less. He spoke about retiring this year after winning the Malaysian Open in January, because of the increasing strain on his body and his mind.
But now the 31-year-old badminton legend has agreed with former world number one Peter Gade, who advised Lee to cut down his schedule if he wanted to play on.
"I saw what Peter Gade said and I think he is right. I must do that," said Lee, well aware that the Dane managed to compete at the highest level in men's singles till past his 36th birthday, "It might just do six tournaments next year."
Lin Dan does it. Since Lin won the Olympic gold medal he has been allowed to compete in very few tournaments, undoubtedly helping him stay fresh enough to win his fifth world title at Guangzhou in August.