The unseeded player edged past Dan 24-22, 21-12 to claim the second BWF World Tour title of his career. Tsuneyama had earlier won the Thailand Open in 2018.
The first game played host to a tight fight between the duo as both players tried to go past each other in a bid to win the set. With the scores tied at 8-8, Tsuneyama picked seven consecutive points to take a considerable lead against his opponent.
However, the two-time Olympic champion kept his calm and fought back to level the score to 17-17. The two went on neck to neck for the next few points as well, with the Japanese getting the better of Dan and winning the set.
Contrary to the first set, Tsuneyama had it easy in the second set as he showed complete domination over the Chinese player and sealed the game, as well as the match.
In the women's singles finals, Sung Ji Hyun was handed a shocking defeat by her compatriot An Se Young. The 17-year old youngster won the match 21-13, 21-17 in 45 minutes.
Young claimed her fifth BWF World Tour title of 2019, and is just one title behind Chen Yufei who, has picked up six titles in 2019. The world No.10 had earlier defeated the top-ranked Akane Yamaguchi in the semifinals on Saturday.
Sixth seed Chinese Taipei pair of Lee Yang / Wang Chi-Lin won the men's doubles title after winning 21-19, 20-22, 21-19 against Malaysia's Goh V Shem / Tan Wee Kiong. The women's doubles title went to Nami Matsuyama and Chiharu Shida after they defeated fellow Japanese pair Misaki Matsutomo and Ayaka Takahashi 15-21, 21-17, 21-18.
The shortest final of the tournament was played between the mixed doubles pair of Tang Chun Man / Tse Ying Suet (Hong Kong) and Goh Soon Huat / Lai Shevon Jemie (Malaysia) as Chun Man and Ying Suet went on to win the match 21-14, 21-15 in just 34 minutes.