The national long-awaited title came after Huy stood on top of the men's 10m air pistol event at the Fuyang Yinhu Sports Centre Shooting Range.
Huy was one of three Vietnamese representatives in this category but the only one qualified for the final.
He shot 580 points to place No 4 in the qualification and joined the final top eight which included powerful rivals from South Korea, India and Uzbekistan.
The 27-year-old continued shining brilliantly to score 240.5 points to take the gold medal, ending Viet Nam's nearly 40-year title drought at the Asian Games.
He earned just 1.1 point more than his runner-up Lee Won-ho from South Korea. Vladimir Svechnikov of Uzbekistan came third with 219.9 points.
"It is complicated feeling in me now. I am happy and felt high pressure after my competition," said Huy who has practised shooting for 11 years.
"I was not worried at all although it was my first major final that I took part in. Despite strong rivals, I just focus on my shoots because I believe that the most important element is technique.
"When it was only the South Korean and I left in the final, I was nervous a little. But I the more I shot the better points I earn. Luckily, I won a gold."
Earlier, Huy and two teammates Phan Cong Minh and Lai Cong Minh finished third in the men's 10m air pistol team event with 1,730 points.
They ranked below India (1,734 points) and China (1,733 points).
The shooting team has now collected one gold and one silver and can grab more medals as shooters will compete in the women's 10m air pistol and men's 50m rifle 3 positions on September 29.
In wushu, Vietnamese athletes pocketed two bronzes in the sanshou events by Nguyen Thi Thu Thuy and Hua Van Doan.
Thuy was ousted in the semi-finals of the women's 60kg class, unexpectedly lost to Indian Roshibina Devi Naorem.
Doan was defeated by Chinese Jiang Haidong in the men's 56kg semi-final match.
Viet Nam Team moved to No 14 in the medal tally with one gold, one silver and 10 bronzes./.