China's Chen Xiaoxin stunned Olympic champion Carolina Marin as she beat the Spaniard in three games to reach the last 16 of the women's singles event at the Badminton World Federation (BWF) Indonesia Open in Jakarta.
Marin, the second seed, had forced her way back into the contest after dropping the opener, but eventually fell to a shock 21-12, 10-21, 22-20 defeat at the Jakarta Convention Center.
After coming through the marathon one hour and four minute contest, Chen will next play Malaysia's Soniia Cheah, who beat Chinese Taipei's Chiang Mei Hui 21-18, 21-11.
Ratchanok Intanon, the 2013 world champion and eighth seed, also crashed out as she was beaten by India's Saina Nehwal.
Nehwal, gold medallist at the 2010 Commonwealth Games and who earned bronze at the 2012 Olympics in London, recovered from the losing the first game to clinch a 17-21, 21-18, 21-12 triumph.
The Indian star will go up against another Thai in Nitchaon Jindapol in the next round.
PV Sindhu, who claimed Olympic silver at last year's Games in Rio de Janeiro, joined Nehwal in progressing as she overcame Pornpawee Chochuwong of Thailand 21-12, 21-19.
The fourth seed will take on American Beiwen Zhang for a place in the quarter-finals.
Top seed Tai Tzu Yung of Chinese Taipei prolonged her stay at the tournament, a World Superseries Premier event, by sweeping aside Minatsu Mitani of Japan 21-8, 21-12.
Tai, the defending BWF Indonesia Open champion, is due to face Gregoria Mariska Tunjung of Indonesia.
Tunjung delighted the home crowd by ousting China's Chen Yufei 17-21, 21-19, 21-19.
Action in the men's singles main draw is scheduled to begin tomorrow.
Perennial Olympic silver medallist Lee Chong Wei, the defending champion, gets his campaign in Jakarta up and running when he meets Tommy Sugiarto of Indonesia.