However, their rivals levelled the result and went on to take the fifth set for the final victory.
Kien and Hue pocketed the fourth silver for Vietnam at the championship.They lost all four finals to players from Singapore.
In the boys’ U18 singles category, Vu Quang Hien will meet a Malaysian player in the semi-final. The other semi-final will be an all-Thailand match.
The 22nd tournament will end on July 13.