North Korean Ro Suk-yong scored 17 points and her effort was matched by South Korean team mates Lim Yung-hui and Park Hye-jin.
Ro admitted that in defence she had struggled at times due to her relatively small stature, but was backed up by the 6-foot-5 U.S.-based team mate Park Ji-su.
"It was difficult when I was trying to defend because I am very short, so when I cannot defend Park Ji-su did it," said Ro, who is one of three North Korean players in the team.
"Although I am feeling a bit tired, I think what's important is we will be playing together in the final. We'll do our best."
The Koreans will face China in Saturday's final and will be followed by dozens of supporters wearing T-shirts with the unified Korean flag.
Fan Angela Won, 26, a South Korean living in the United States, said: "It was just amazing to see the two teams play together as one."
Cho Yeong-been from Seoul said watching a unified outfit felt "very different" from seeing the South Korean team, noting fans from different areas contributed songs from different regions.
Lee Joo-young, a Korean based in Jakarta, said she does not usually watch sports, but came to cheer on the unified team.
"I want to support the One Korea team. They have played as a unified team," she said.
The Koreas marched together under a common flag at the opening ceremony and they have also fielded joint teams in rowing and canoeing, wining a gold and two bronzes so far.
A unified Korean ice hockey team also competed at this year’s Winter Olympics in Pyeongchang.
Korea expert Andray Abrahamian said that the good run by the basketball team would be welcomed by both countries "especially since sports and culture are the main avenues for cooperation between the two Koreas at the moment."
He noted that North Korean leader Kim Jong-un, who is a basketball fan, had invested significantly in sports in North Korea.
"Cooperation will probably be limited to that area until a breakthrough on denuclearisation and sanctions can be found," said Abrahamian, an adjunct fellow at Korea University.
(Reporting by Fransiska Nangoy, Angie Teo, Fanny Potkin and Jessica Damiana; Writing by Ed Davies and Pritha Sarkar)
