Chuyen, 24, was the first female to win the prize at the contest, thefourth of its kind for those between 18 and 25 years of age.
However, the contest, first held in 2004, was marred by controversy surrounding the voting system.
Many people in the audience and at home said they did not receive confirmation of their votes from contest organisers.
Others said they got a message saying "voting is closed" despite texting their votes well within the time limit.
In recent years, many music shows, contests and awards such as MorningStar – A Rendezvous, Green Wave and Golden Album, have relied on publicvotes, via texting, ratings and online voting.
This year, the competition, spread over nine consecutive Sundays, attracted 700 hopefuls, many from rural areas.
Chuyen is in her third year at the Military Culture & Arts College .
Two other contestants, Dinh Manh Ninh and Ha Hoai Thu, received complementary prizes as the most promising singers./.