The first major assault by Japanese troops on Guadalcanal, Solomon Islands by Colonel Kiyonao Ichiki and his 770 men commenced at about 0000 hours with poor intelligence that led him to severely underestimate American strength. At 0130 hours, a wave of 100 Japanese troops rushed across the river, supported by machine guns and mortar fire, only to be mowed down at the line manned by 2,500 Marines. At 0230 hours, another wave of 150 to 200 Japanese rushed again, suffering similar fates. A third wave attacked at 0500 hours, again suffering near 100% casualty rate. At 0700 hours, US 1st Marine Regiment counterattacked supported by light tanks and aircraft, enveloping and destroying the remnants of 2nd Battalion of Japanese 28th Infantry Regiment. The Battle of the Tenaru (Ilu) River ended with the Japanese suffering 740 killed (including Ichiki) and 15 captured; the Americans suffered 44 killed. During the day, men of the 2nd Battalion of the US 5th Regiment arrived at Guadalcanal from Tulagi as reinforcements
