The Vietnamese-Japanese pair, which was seeded No. 4, lost 6-7 (3), 2-6 to No. 3 seeds Francis Casey Alcantara of the Philippines and Sem Verbeek of the Netherlands in the doubles’ final match.
Earlier, Nam was defeated 6-7 (4), 1-6 by No. 1 player Ramkumar Ramanathan of India in the singles’ semi-finals.
Ramanathan went on to win the title after beating Nicholas Hu of the US 7-6 (4), 6-2 in the final.
Nam and his teammate Trịnh Linh Giang will participate in the Thailand F2 tournament from June 12 to June 18.
Nam is the No. 5 seed in the singles event and will play Kittiphong Wachiramanongwong of the hosts in the first match.
Giang will face Kelsey Stevenson of Canada.