Ratchanok Intanon’s defence of her BWF Indonesia Open women's singles crown came to an abrupt end today ©Getty Images

Ratchanok Intanon’s defence of her Badminton World Federation (BWF) Indonesia Open women's singles crown came to an abrupt end today as the Thai suffered a shock first-round defeat against China’s Sun Yu.

The second seed lost 21-15, 21-18 after 45 minutes at the Istora Gelora Bung Karno Stadium in Jakarta.

Unseeded Sun’s reward is a second-round meeting with home favourite Febby Angguni, who overcame Hong Kong’s Yip Pui Yin 18-21, 21-16, 21-19.

Intanon was the only women's singles seed to suffer defeat today with top-ranked Carolina Marin of Spain beating Indonesia’s Hera Desi 21-18, 21-11.

Reigning Olympic champion Li Xuerui of China, the third seed, came from behind to register a 16-21, 21-8, 21-11 victory over Indonesia’s Ruselli Hartawan, while eighth seed Saina Nehwal of India was made to work hard for her 21-11, 19-21, 21-15 success against Chinese Taipei’s Pai Yu-po.

Women's singles top seed Carolina Marin eased into the second round
Women's singles top seed Carolina Marin eased into the second round ©Getty Images

In the mixed doubles, defending champions Xu Chen and Ma Jin of China beat Indonesia’s Hafiz Faisal and Shella Devi Aulia 21-16, 21-16 in 29 minutes.

Unseeded Alfian Eko Prasetya and Annisa Saufika delighted the home crowd by beating seventh-ranked Chris Adcock and Gabrielle Adcock of England 24-22, 18-21, 21-16.

There was disappointment, however, for Indonesian veterans Markis Kido and Pia Zebadiah Bernadeth as they lost to China’s Liu Yuchen and Tang Jinhua 21-9, 21-9.

The first round of the men’s singles is due to take place tomorrow.

The event in Indonesia's capital is part of the BWF Superseries.