Thanh finished first in the women’s category in the event which ended in Switzerland on Sunday with a time of 328 hours 27 minutes and 55 seconds.
She swam 38km, cycled 1,800km and ran 422km over 14 days.
Because the event was so harsh and extremely challenging, there were just 23 athletes from all over the world taking part, 19 men and four women.
Thanh was the only representative of Vietnam in this tournament.
She said: “This was a very special experience indeed. During the race, there were many athletes from many different countries. Athletes often exchanged, shared experiences and inspired each other. Cycling at night also made us feel very sleepy, so we rode and talked to each other.
“President of the World Triathlon National Federations told me that in the past 30 years, only around 100 people have completed the World Champion Deca Ultra Triathlon. It was certainly not easy to complete this event, sometimes it seemed like I couldn’t do it.”
Notably, a 60-year-old woman from France, Nadine Zacharias also completed this race.
Meanwhile, the champion of the men’s category was Kenneth Vanthuyne of Belgium who only needed eight days to finish all categories.
Thanh was born in 1990 in Hanoi. She is known as “the girl who runs around the world”, or “desert rose”. In 2016, she became the first Asian to run through the four harshest deserts in the world with a total distance of 1,000km.
They were the Atacama Desert in Chile, Gobi Desert in China, Sahara Desert in North Africa, and the Antarctica Desert in Antarctica.
Most recently, Thanh completed a challenging mountain run at the Everest Trail Race.
According to thestar.com.my