DuBose then sailed for Aleutian Islands to counter a Japanese force there but were recalled to Pearl Harbor two days later. With the upcoming Guadalcanal campaign, "Portland" provided naval bombardment of Japanese positions during the amphibious landings at Tulagi and Guadalcanal from August 7–9, 1942 and then participated in the Battle of the Eastern Solomons. DuBose skilfully commanded "Portland" during latter battle and inflicted heavy damaged on Japanese air group without damage to his own ship. For his service during the battle, he was decorated with Navy Commendation Medal with Combat "V".