The second seed and world No 335 Kwon, 19, relied on his consistent baseline game to beat the error-prone Altmaier, one year his junior, in only 74 minutes for his fifth ITF singles win.
Kwon who reached his career highest at No 286 last month lifted up his first two titles in Cambodia last year. The Saturday’s win was his third this season, having won in Japan and at home in South Korea before Hua Hin.
The South Korean will play his last event of the year in the Thailand Men’s Futures 6 which starts this Monday in Hua Hin. He will be seeded fouth behind Kazakh Dmitry Popko, Frenchman Sadio Doumbia, and Chen Ti of Taiwan.