Swimming in lane seven, Vien was at an early disadvantage as she finished sixth during the semi-finals. After the first 50m she was fifth before she pulled of Igarashi Chihiro of Japan.
In the last 50m Vien squeezed past Aoki Tomomi, also of the hosts, to finish third.
Chen Duo of China came first, winning gold medal in 1 minute 56.71 seconds while her fellow Chinese Al Yanhan grabbed sliver in 1 minute 57.35 seconds.-VNA