The doubles experts came back from a lapse in the second set tie-break to win the final showdown 6-2 6-7 (5-7) 10-6 in one hour and 22 minutes.
The Thai pair proved mentally tougher at crucial stage especially at 8-6 in the super tie-break set. They tightened their defence by responding to five overhead smashes from the opponents until the impatient Hsieh overhit the next smash to face the match point.
The Taiwanese shouted in anger and sit in disbelief to waste a chance to reduce the gab. The twins then closed off the deal with a winner to the baseline that left both opponents in stranded.
Last week Sanchai had to pair up with a different partner in Yokohama as his brother was committed to a local Military Games.
Since the start of the year, the sibling won three Challenger titles, the first in Bangkok in January and the second last month in Kyoto. Apart from the winning prize money of US$4,650, both will return to the top 90 when the ATP rankings are updated on Monday.
They will next head to Quanzhou for another ATP Challenger which starts on Monday.