No 2 seed Duc lost 3-6, 6-3, 3-6 to Eita Ishikawa of Japan in the U18 event.
He received 26 points and will advance to the world junior top 500 today.
In other news, Ly Hoang Nam was eliminated from the M15 Sharm El Sheikh after being defeated 4-6, 5-7 in the semi-finals by No 3 seed David Poljak of the Czech Republic on February 29.
Nam wasted eight out of nine break points. He grabbed four points to improve his current world ranking of No 710.
Vietnam's No 1 player will fly to Morocco to unite with teammates to take part in the Davis Cup World Group II play-offs which will be held from March 6-7.
VNA/VNP
