The First Battle of Naktong Bulge was an engagement between United Nations Command (UN) and North Korean forces early in the Korean War from August 5–19, 1950 in the vicinity of Yongsan (Yeongsan, Changnyeong county) and the Naktong River in South Korea. It was a part of the Battle of Pusan Perimeter, and was one of several large engagements fought simultaneously. The battle ended in a victory for the UN after large numbers of US reinforcements destroyed an attacking North Korean division.
On August 5, the Korean People's Army (KPA), 4th Infantry Division crossed the Naktong River in the vicinity of Yongsan, attempting to cut UN supply lines to the north as well as gaining a bridgehead into the Pusan Perimeter. Opposing it was the 24th Infantry Division of the Eighth United States Army. Over the next two weeks, US and KPA forces fought a bloody series of engagements inflicting heavy casualties on one another in a confusing series of attacks and counterattacks, but neither side was able to gain the upper hand. In the end, the US forces, aided by reinforcements, air support and heavy weapons, destroyed the KPA force which was hampered by lack of supply and high desertion rates.
The battle was a turning point in the war for the KPA, which had seen previous victories owing to superior numbers and equipment. UN forces now had a numerical superiority and more equipment, including M4 Sherman tanks and heavy weapons capable of defeating the KPA T-34 tanks.