Track and field athlete Nguyen Thi Thanh Phuc won a bronze medal in the Asian Race Walking Championship in Japan on Sunday.
She finished the 20km event in 1 hour 35 minutes – three minutes inside the Olympic B Standard qualifying time.
The 21-year-old could be the first track and field athlete of Viet Nam to secure a berth at the Olympics.
Da Nang City-born Phuc previously won a gold medal at the 26th Southeast Asian Games in Indonesia last year with a time of 1:43.22.
Viet Nam Athletics General Secretary Hoang Manh Cuong said: "Phuc's winning a ticket to the Olympics is good news. I hope her achievement will be a driving force for other athletes."
So far, two Vietnamese taekwondo martial artists, one judoka, two gymnasts and two shooters have won places at this year's games.-VNS