Birmingham: India's Saina Nehwal had to go the full distance of three games to overcome American qualifier Beiwen Zhang 24-22, 18-21, 21-19, and enter the quarter-finals of the women's singles at the All-England badminton championships.
Saina needed an hour to get past a fighting Zhang, who is a China-born former Singapore player, here Thursday night.
Saina now plays fourth seed Wang Shixian of China, who easily beat Chloe Magee of Ireland 21-15, 21-12.
The seventh-seeded 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 No.11 Juliane Schenk.
Saina's compatriot and 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 in 47 minutes.
Wang Shixian and Wang Yihan continued to look the pick of the Women's Singles challengers.
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.
Bae Yeon Ju of Korea had to play three games against Thailand's Porntip Buranaprasertsuk before sailing through 21-11, 19-21, 21-13.
In the men's singles, Hans-Kristian Vittinghus squeezed past Thailand's sixth seed Boosak Ponsana, 18-21, 21-12, 21-19 to enter the last eight.
Top seed Lee Chong Wei of Malaysia and second-seeded Chinese Chen Long won through their second round matches in straight sets.
Others still in the hunt are China's defending champion Chen Long and team-mate Wang Zhengming, world No.1 Lee Chong Wei, Japan's No.5 seed Kenichi Tago and his young compatriot, Kento Momota, Lee Dong Keun and Son Wan Ho of Korea.
Momota ended the aspirations of England's Rajiv Ouseph, 21-15, 21-10, while Son earned a 21-16, 14-21, 21-10 victory over Indonesia's Dionysius Hayom Rumbaka in an hour.
It took almost until midnight, but Japan's Reika Kakiiwa and Miyuki Maeda snapped the stunning winning streak of China's Bao Yixin and Tang Jinhua in the Women's Doubles, denying them an eighth successive title.
In an epic tug-of-war, played out over an hour and 40 minutes the blend of experienced Maeda and her younger spirited partner finally broke the resolve that saw Bao and Tang wrest seven titles in a row, starting with the Dutch Open last October.
Eventually, Kakiiwa and Maeda found an extra gear to seal the match on their third match point, 21-16, 21-23, 21-17.
The results (prefix number denotes seeding):
Men's singles (2nd round): Wang Zhengming (China) beat Gao Huan, (China) 21-19, 21-17; Kento Momota (Japan) beat Rajiv Ouseph (England) 21-15, 21-10; 5-Kenichi Tago (Japan) beat Chou Tien Chen (Chinese- Taipei) 21-19, 21-15; 1-Lee Chong Wei (Malaysia) beat Chong Wei Feng (Malaysia) 21-6, 21-12; Son Wan Ho (South Korea) beat Dionysus Rumbaka (Indonesia), 21-16, 14-21, 21-10; Lee Dong Keun (South Korea) beat Sho Sasaki (Japan) 21-19, 21-16; Hans-Kristian Vittinghus (Denmark) beat 6-Boonsak Ponsana (Thailand) 18-21, 21-12, 21-19; 2-Chen Long (China) beat Takuma Ueda (Japan) 21-14, 22-20.
Women singles (2nd round): 6-Bae Yeon-Ju (South Korea) beat Porntip Buranaprasertsuk (Thailand) 21-11, 19-21, 21-13; 5-Sung Ji-Hyun (South Korea) beat Lindaweni Fanetri (Indonesia) 23-21, 21-11; Michelle Li (Canada) beat Bellaetrix Manuputty (Indonesia) 21-15, 21-23, 21-16; 2-Wang Yihan (China) beat Yu Sun (China) 21-11, 21-14; 3-Ratchanok Intanon (Thailand) beat Han Li (China) 18-21, 21-12, 21-11; 7-Saina Nehwal (India) beat Zhang Beiwen (US) 24-22, 18-21, 21-16; 4-Wang Shixian (China) beat Chloe Magee (Ireland) 21-15, 21-12; 1-Li Xuerui (China) beat Minatsu Mitani (Japan) 14-21, 21-19, 21-15.