Duo Pham Thanh Phuong Thao and Ton Nu Hong An won their matches against the Filipino masters, their fifth win in a row, to take top spot with still one game to play.
On their way to gold, they beat Cambodia, Myanmar, Malaysia and Thailand at the Royal University of Phnom Penh.
The impressive performance of the team makes them early champions even though they still have one match to play on May 6 against Laos.
The victory ceremony will take place on that day.
"I am happy to get the gold medal which is my first time winning at a SEA Games," said Thao.
"Masters from Thailand and the Philippines are really strong. They are calculating style players. We have to think carefully when facing them."
It is the first time ouk chaktrang, the traditional chess of Cambodia, has been held at the SEA Games. It is widely known among Khmer communities including those in Vietnam.
It is quite similar to international chess with difference in the way of pieces move and also some regulations.
It is the first sport to open the 32nd Games. The competitions are taking place from April 29 to May 9 with seven events.
Vietnamese masters have only been learning ouk chaktrang for about eight months in preparation for this tournament.
"My switching from international chess to ouk chaktrang was accidental. My coach introduced me to this new chess and I found it really interesting so I want to test my skills," said Thao who has been FIDE-master since 2009 at the age of 10.
In addition to this gold, Vietnamese masters will also win medals in the men's rapid event as they are in the leading group with only one match left./.
