Tanihara, 26, held of two late charges by Yusaku Miyazato (65) and Charlie Wi (64) to win the $186,000 first place prize.
Jumbo Ozaki, who was in contention entering the final round, could only muster a closing 2-over 74 to finish in ninth, four shots back.
Seven players, including Miyazato and Wi, tied for second at 6 under for the tournament. Also in that group was Ted Oh, Chung Joon, Simon Yates, Tsuyoshi Yoneyama and the leader coming into Sunday, Hiroshi Goda.
Goda, who also finished runner-up last year, posted a 3-over 75.
Thongchai Jaidee, winner of last week's Volvo Masters of Asia, closed with a 3-under-par 69 to tie for 10th.