Wang, a double Summer Universiade gold medallist, was beaten 21-19, 10-21, 21-16 by the unseeded Thai player on the opening day of the event at the Yeomju Gymnasium.

Wangcharoen will hope to continue his progress at the event, part of the BWF Grand Prix Gold series, when he takes on South Korea's Jong Soo-hwang in the next round of the men's singles tournament.

Jong reached round two with a comfortable 21-16, 21-17 win over Jia Wei Tan of Malaysia.

Top seed Son Wan-Ho also enjoyed a serene opening to the tournament as he beat Hsueh Hsuan Yi of Chinese Taipei in straight games.

Son, bronze medallist at the World Championships in Glasgow earlier this year, got his title defence off to a near-perfect start as he recorded a commanding 21-19, 21-12 victory against Hsueh.

South Korea's Kwang Hee-heo, a 21-8, 21-17 victor over Andrew Rouse of New Zealand in his first match, awaits for compatriot Son in the next round.

Third seed Tanongsak Saensomboonsuk of Thailand joined Son in the last 32 as he overcame Russia's Pavel Kotsarenko 21-13, 21-17.

Saensomboonsuk is due to face Panji Ahmad Maulana after the Indonesian player defeated Hyun Seok-jang of South Korea 21-17, 23-25, 21-18 in a match which lasted two minutes shy of an hour.

The event in Gwangju is due to continue tomorrow with the first day of the women's singles event and second round matches in the men's singles.