
The 17-year-old from Chiang Mai's Montfort College, jumped a personal best of 7.65m in his second attempt to reign supreme in the discipline which attracted 15 competitors including two Americans.
Pre-race favourite Stefan Brits from South Africa finished second after covering 7.57m, with German Yannick Roqqatz in third place in 7.53m.
Supanara was the lone Thai athlete to test his mettle in the July 8-12 world-class competition. His brilliant form also bettered the Japanese Konishi Yasumichai's gold-medal attempt of 7.52m in the previous championship in Ostrava, Czech Republic two years ago.
However, the Thai youngster's record was a far-cry from the previous world standard of 8.25m established in La Habana in 1986 by Cuban Luis Bueno.