The 29-year-old, a high school English teacher in the northern Phu Tho Province, is the first Vietnamese and youngest ever to make the short list.
The other nine are from Brazil, India, Italy, Malaysia, Nigeria, South Africa, South Korea, the U.K. and the U.S.
The finalists were announced at 0:10 a.m. Wednesday (Hanoi time) by the Varkey Foundation, the London-based charity that gives the award.
Phuong said she exploded with joy on hearing her name among the finalists.
"I cried like a child in the middle of the night. I was so surprised to make it to the top 10."
It is a huge deal since it not only reflects her own efforts but also those of her students in a remote area, she said.
Earlier this year, when she made it to the top 50, she was congratulated by Minister of Education and Training Phung Xuan Nha, who described the award as "the Nobel Prize for education."
Phuong, an ethnic Muong, decided to become an English teacher after watching a Vietnamese documentary on how teachers knocked on people’s doors in remote mountainous areas to persuade them to send their children to school.
She had been offered a position as a representative director of a Pakistani pharmaceutical firm in Vietnam, but turned it down to pursue a career as an English teacher.
In 2016 she quit her previous job as an English teacher at a major language center in Hanoi and an interpreter to teach at the Huong Can high school in Phu Tho, where 90 percent of students are from ethnic backgrounds.
They have little chance to practice English with foreigners, which often leads to low language competence, shyness, poor intercultural awareness, and lack of interest.
Phuong taught herself how to utilize IT to connect teachers and students, even from different countries.
She also makes use of films and online classes, even creating a YouTube channel to teach English for free.
Known as the ‘Industry 4.0 teacher,’ she has taught students in four continents - Africa, Europe, Asia, and America - and is an active member of a Microsoft educational community of global teachers that designs lessons and engages in professional development.
She is writing books to help her students graduate high school, teaching on TV, running the YouTube channel, helping other teachers, and supporting children in their education endeavors.
The Varkey Foundation, established in 2010, seeks to improve education standards and raise the status and capacity of teachers around the world.
The Global Teacher Prize, established in 2014, carries a top prize of $1 million. This year it received 12,000 applications from around the world.
Last year Tran Thi Thuy from the northern Hung Yen Province made it to the top 50.