Luu Thi Duyen has missed her chance to qualify for the London Olympic this summer.
She was defeated 13-28 by American Marlen Espazra in the last 16 of the 51kg category at the seventh AIBA Women's World Boxing Championships in Qinhuangdao, China on Tuesday.
The top eight athletes in the 51kg, 60kg and 75kg event will earn tickets to the Games, according to the rules.
Earlier, Le Thi Nhung lost 6-20 to Thai Sudaporn Seesondee in the first round of the 75kg.-VNS