The Vietnamese came first in the men’s discus with a result of 48.09m, setting a new personal best.
Eric Yee of the hosts was second with 45.94m while Albert Mantua from the Philippines came third with a throw of 45.69m.
Earlier, Luong Duc Phuoc took home a bronze in the men’s 800m. The 17-year-old finished at 1:56.14.
He was behind Nishikubo Tatsuy of Japan who ran 1:50.83 and Marco Vilog of the Philippines on 1:51.63.
In other events, Nguyen Van Khanh and Vuong Ngoc Tuyet earned their berth in the final of the women’s 200m category.