China's world number three Wang Zhi Yi overcame severe cramps to down Indian star P.V. Sindhu and reach the quarter-finals of the BWF World Championships on Thursday.
Top seeds kept their campaign on track with South Korea's world number one An Se-young and defending champion Akane Yamaguchi also winning their round three matches at New Delhi's Indira Gandhi Indoor Stadium.
But Wang's brave effort stood out as she beat ninth-seeded Sindhu 21-11, 15-21, 21-17 despite severely cramping in the deciding game and stun the home crowd.
With scores level at 16-16 in game three, Wang slipped and winced in pain before taking some treatment for cramps.
The Chinese went down again at 19-17, but this time got back to get the winners as she fell flat on the court in relief and joy.
"Obviously it was such a tough match today," said Wang. "I think she is very strong opponent and has very fast attacks. My gameplan worked and I am proud of my performance today."
On her cramps, Wang said, "That moment I just told myself to keep going. Never give up - that's it."
Sindhu added: "I don't know if she was injured or not. Maybe that's her strategy or her way of doing it. You never know, maybe that's her gameplay."
An eases through
Earlier Olympic champion An beat Denmark's Mia Blichfeldt 21-16, 21-10 in 43 minutes in New Delhi as she bids to win a second world crown.
An, who pulled out of the Japan Open in the second round last month with a foot issue, made a slow start but soon found her groove against the 16th-seeded Dane.
"I am very happy, the crowd was supporting me and that gave me energy and keeps me going," the 2023 champion An said.
Japan's world number two Yamaguchi beat Sim Yu-jin of South Korea 21-17, 21-10 to stay on course to defend her title she won last year in Paris.
Japanese Nozomi Okuhara served past Ishika Jaiswal of Malaysia 21-11, 13-21, 21-12.
In men's singles action, Indian giantslayer Ayush Shetty's dreamrun in the tournament ended with a 21-19, 21-11 defeat to Ali Farhan of Indonesia.
Shetty, who knocked out defending champions Shi Yuqi of China in round one, fought hard but 11th-seeded Farhan showed his class in the round-of-16 match.
Taiwan's Chou Tien Chen beat Yushi Tanaka of Japan 21-14, 21-9.
American teenager Garret Tan lost to Thailand's Kunlavut Vitidsarn a day after the 18-year-old caused a big upset to send India's Lakshya Sen packing in a three-game thriller.
World number two Vitidsarn outplayed world championship debutant Tan 21-10, 21-10.
