With support of the hometown fans, number three-seeded Nam defeated the six seed, Robert Strombachs of Germany, 2-0 (6-4, 6-2) in the quarterfinals.
Nam is world number 476 in the ATP rankings, while Strombachs is number 621.
Earlier, Tay Ninh–born Nam made it to the semifinals of the Vietnam F4 Futures.
Nam will next face Yu Cheng-Yu of Chinese Taipei, who beat Rai Ajeet of New Zealand (6-4, 6-2) in his quarterfinal matchup.
Nam won the men’s doubles title at the Vietnam F4 Futures. However, he missed the men’s singles title following a loss to Roman Safiullin of Russia in the final.