The battalion did not take part in any fighting until a few months later when, in January 1943, it took part in the defence of Wau after the 17th Brigade was despatched to reinforce Kanga Force. Sailing to Port Moresby from Milne Bay on the MV "Duntroon", an advance party of two companies from the battalion was flown into Wau on 24 January to hastily reinforce the small force around Ballams. The remainder – totalling about 450 men – arriving on 29 January, after which they secured the airfield, which was now under direct Japanese fire, as the two companies that had arrived earlier were pulled back from Ballams. In early February, as the Australians gained the initiative, the battalion was relieved from holding the airfield, and went on the offensive, attacking alongside the 2/7th Battalion, in an effort to push the Japanese away from their positions on the bank of the Bulolo River, around Crystal Creek, to the south-west of Wau. The fighting was intense, and over the course of three days, the battalion lost 27 killed and 31 wounded.