Coach Naruephon Kaneson said on Friday the Thai women's football team are ready to face Vietnam in the final.
The Chaba Kaew defeated Myanmar 1-0 in the semi-finals on Thursday with substitute Orapin Waenngoen scoring the winner late on.
They will meet Vietnam in the gold medal match on Sunday.
"Our aim is to win the gold medal. We missed out on the gold medal in the previous Games and we want to win it this time," Naruephon said.
"It's good that we meet Vietnam in the final. This will prove that who is better in Asean because our world rankings are very close."
Thailand finished second at the 2017 SEA Games in Malaysia.
Vietnam took the gold medal only because they had a better goal difference after a round-robin contest.
Thailand drew 1-1 with Vietnam in the group stage at Philippines 2019.
"Both teams are well prepared for this Games. We did better in training than in matches and we believe we can do better," Naruephon said.
"We have to solve our problems and won't make any excuses [if we lose in the final]."
Orapin said: "I felt a bit nervous when I came on as a substitute as we were yet to score. When I scored, we felt relieved and confident.
"This is my first SEA Games and I am very happy to score the winning goal in the semi-finals. We will do our best to take the gold medal to our country."
Thailand and Vietnam are the most successful nations in women's football at the SEA Games with each winning five titles. However, Thailand are the only Southeast Asian team to have played at the Fifa Women's World Cup.