Following intensive training, the 25th began moving to Guadalcanal, 25 November 1942, to relieve Marines near Henderson Field. First elements landed near the Tenaru River, 17 December 1942, and entered combat, 10 January 1943, participating in the seizure of Kokumbona and the reduction of the Mount Austen Pocket in some of the bitterest fighting of the Pacific campaign. The threat of large enemy attacks caused a temporary withdrawal, but Division elements under XIV Corps control relieved the 147th Infantry and took over the advance on Cape Esperance. The junction of these elements with Americal Division forces near the cape, 5 February 1943, ended organized enemy resistance.