Indonesia's Panji Ahmad Maulana sprung a surprise as he beat third seed Tanongsak Saensomboonsuk of Thailand ©Getty Images

Indonesia's Panji Ahmad Maulana sprung a surprise as he beat third seed Tanongsak Saensomboonsuk of Thailand to reach the third round of the Badminton World Federation (BWF) Korea Masters in Gwangju.

Maulana produced a superb display as he dispatched his Thai opponent 21-14, 21-13 at the Yeomju Gymnasium.

The Indonesian will take on Lin Chia Hsuan of Chinese Taipei in the last 16 tomorrow.

Maulana's team-mate Firman Abdul Kholik also caused an upset as he knocked out Hsu Jen Hao of Chinese Taipei, the sixth seed, with a 21-15, 21-13 success.

Defending champion and top seed Son Wan-Ho, a World Championships bronze medallist in Glasgow earlier this year, bucked the trend of surprise results by cruising into the third round.

Son won 21-10, 21-14 against compatriot Kwang Hee-heo to set up a meeting with Kim Min-ki.

The unseeded players also struggled in the women's event as China's Gao Fangjie stunned fourth seed Busanan Ongbumrungpan.

China's Gao Fangjie caused an upset in the women's singles tournament ©Getty Images
China's Gao Fangjie caused an upset in the women's singles tournament ©Getty Images

The unseeded Chinese player battled back from a game down to beat Thailand's Ongbumrungpan 11-21, 21-15, 21-17.

Ji Won-bae of South Korea awaits for Gao tomorrow after she overcame Laura Sarosi of Hungary 21-15, 19-21, 21-15.

Sixth seed Fitriani Fitriani of Indonesia also crashed out in the first round of the BWF Grand Prix Gold event as she lost 21-18, 16-21, 21-16 to Sonila Cheah of Malaysia.

Fitriani's opponent in the last 16 will be China's Zhiyi Wang.

Women's top seed Song Ji-hyun, World Championships bronze medallist in 2015, had no such problems as she booked her place in round two with a 23-21, 21-10 victory over Ye Ji-kim.

Song will face Zhang Yiman of China tomorrow after she swept aside Sung Sho-yun 21-17, 21-13.