Her support of the invasion of Bougainville began on the night of 31 October 1943, when her task force sortied from Port Purvis to neutralize the Japanese airfields at Buka with heavy gunfire. "Charles Ausburne" fired on shore batteries here and on the Shortlands, which the task force passed on its way south to refuel. In the early morning of 1 November, troops stormed ashore at Empress Augusta Bay, and word was received of the movement of four Japanese cruisers and six destroyers south from Rabaul to attack the transports off Bougainville. Immediately, "Charles Ausburne" and her force put north to meet and engage the enemy. First contact was made at 02:27, 2 November, when the targets were clear on the flagship's radar, and "Charles Ausburne" and three other "Little Beavers" maneuvered for a torpedo attack, which the Japanese evaded. Next, they finished off , already blazing from the attack of American cruisers, then sped at 32 knots to close on . With joining in the attack, "Charles Ausburne" sank the enemy destroyer, then dashed to the assistance of torpedo-damaged whom she escorted back to Purvis Bay at the close of this Battle of Empress Augusta Bay.