High Quality Content by WIKIPEDIA articles! The Battle of Yongsan was an engagement between United Nations (UN) and North Korean (NK) forces early in the Korean War from September 1–5, 1950, at Yongsan in South Korea. It was part of the Battle of Pusan Perimeter and was one of several large engagements fought simultaneously. The battle ended in a victory for the United Nations after large numbers of United States (US) and South Korean troops repelled a strong North Korean attack.