After Lae had fallen sooner than the Allies had anticipated, they exploited the advantage. As a result of faulty intelligence, which underestimated the size of the Japanese force in the area, the assault force chosen consisted of only Brigadier Victor Windeyer's 20th Infantry Brigade. The landing at Scarlet Beach that took place on 22 September 1943 was the first opposed amphibious landing that Australian forces had made since the Landing at Anzac Cove in the Gallipoli Campaign of 1915. Navigational errors resulted in the troops being landed on the wrong beach, with some of them coming ashore at Siki Cove and taking heavy fire from the strong Japanese defences in pillboxes. After re-organising, the Australians pushed inland. The Japanese put up stiff resistance on the high ground at Katika, but were forced back. By the end of the day, the Australians had secured their objectives. The Japanese launched a retaliatory air raid on the ships of the VII Amphibious Force, but US fighter aircraft defended the convoy and no ships were hit. Continued Japanese air attacks on the beachhead inflicted numerous casualties over the course of the battle.