Lieutenant Colonel Brunelli took part in the Battle of Tinian one month later and following the promotion of regiment's commanding officer, Franklin A. Hart at the end of August 1944, Brunelli assumed temporary command of the 24th Marine Regiment. All of the 4th Marine Division's units had been weakened by combat and were ordered back to Hawaii for rest and refit. He led the 24th Marines to Maui and subsequently passed command to the regiment's new commanding officer, Colonel Walter I. Jordan, on September 7, 1944.