Top Vietnamese female swimmer Nguyen Thi Anh Vien failed in the semi-final of the women's individual 200m medley of the 2015 World Swimming Championship in Kazan, Russia, on August 2.
She clocked a time of 2:13.29 to rank 15th among 16 athletes in the category.
However, Vien's result was better than her own SEA Games record of 2:13.53, which she set in Singapore in June.
In the qualifying round, the 18-year-old ranked fifth with a time of 2:13.41.
Eight top swimmers in this division, including Katinka Hosszu of Hungary, Siobhan-Marie O'Connor of Great Britain and Kanako Watanabe of Japan will compete in the final on August 3.
Vien, who won one gold and two silver medals at the Youth Olympics last year, will continue taking part in the women's 400m medley and 400m freestyle.
Vietnam sent four representatives to compete in Russia, including Lam Quang Nhat, Hoang Quy Phuoc and Tran Duy Khoi.
Phuoc, who gained two B standards in the men's 100m and 200m freestyle to 2016 Olympics in Brazil, will compete in the 200 freestyle on August 3.-VNA
Vietnamese swimmer wins gold in US
Vietnam's top swimmer Nguyen Thi Anh Vien won a gold at the NASA Junior Championship Cup.