After a short period of preparation, the 20th Brigade's landing took place on 22 September 1943. It was the first opposed amphibious landing that Australian forces had made since Gallipoli. Navigational errors resulted in the troops being landed on the wrong beaches, with some of them coming ashore at Siki Cove and taking heavy fire from the strong Japanese defences in pillboxes and behind obstacles. After re-organising on the beach, the Australians pushed inland. The Japanese put up stiff resistance around the high ground at Katika, but were eventually forced back. By the end of the day, having suffered 94 casualties, the Australians had secured a beachhead "several kilometres" deep. Late in the day, a force of around 30 Japanese bombers, escorted by up to 40 fighters, from the Wewak-based 4th Air Army based was sent to attack Allied shipping around Finschhafen. Forewarned by the destroyer , which was serving as an air picket and fighter controller in the Vitiaz Strait, the Allies were able to concentrate five squadrons of US fighter aircraft over the convoy and in the aerial battle that followed 39 Japanese aircraft were shot down and the raid turned back.