After easily winning the second stage, That was holding all four jerseys, yellow, green, red, and purple.
The rest of the Vietnamese team had the task in the 89-km last stage from Rayong to Dok Krai Reservoir of helping That win the title.
In sprint 1, Thailand's Maneephan Julatip tried to get ahead of That and claim the Green Jersey but did not succeed as the Vietnamese cyclist accelerated in time to remain ahead.
Vietnam then faced tough challenges from Thailand, South Korea and Malaysia, and ended up losing sprints 2 and 3.
With 20 km left the South Koreans put on a burst, and the Thai and Malaysian cyclists also pulled ahead of the Vietnamese. South Koreans Lee Eunhee and Na Ahreum managed to leave the rest behind at a slope to reach the top along with Thailand’s Chaniporn, Indonesia’s Delia Ayustina and Malaysia’s Nur Aisyah.
The five of them maintained a safe distance from the chasing pack, and That could not catch up with them despite her best efforts and support from her teammates.
Lee won first place for the stage, Ayustina finished second and Aisyah third.
Lee also secured the Yellow Jersey of the entire race with a time of 6 hours 2 minutes 38 seconds. That finished fifth in 6 hours 3 minutes 13 seconds.
She also lost the Purple Jersey for the best Southeast Asian cyclist to Aisyah.
She kept the Green Jersey for the best sprinter and Red Jersey for the best climber.
The Princess Maha Chakri Sirindhorns Cup Women's Tour of Thailand, commonly known as the Tour of Thailand, is part of the professional UCI (International Cycling Union) Asian Tour.
It has three stages of 70 km, 82.2 km and 89 km over relatively flat terrain except for the occasional slope.
Besides Vietnam there were two teams from Thailand, others from Malaysia, Singapore, Indonesia, South Korea, and Taiwan and four clubs.