Nam lost 6-7 (4), 3-6 to Jonathan Gray of England in the singles final match, which went on for over two hours.
The Vietnamese, who is the No. 6 seed here, was expected to win his first title on the home turf after beating No. 2 seed, Sanjar Fayziev, of Ukraine and No. 3 seed, Enzo Couacaud, of France in previous matches. But he appeared too tired to win against Gray, an unseeded player. Gray beat No. 4 seed, Sasi Kumar Mukund, of India in the semi-finals.
In the doubles event, a mixed pair of Miliaan Niesten from the Netherlands and Francesco Vilardo of Italy, the No. 4 seed duo, won 6-2, 7-6 (3) over No. 1 Daniiar Duldaev of Kyrgyzstan and Fayziev to take the title.
Players will continue with the F3 competition from November 20 to 26 at the same venue.