In June 1945, the 8th Battalion was transferred to the Bougainville campaign, where it operated to contain Japanese forces on the Bonis Peninsula It was here that Partridge performed a deed for which he received the Victoria Cross (VC), the highest award for gallantry that could be awarded to British Commonwealth forces.
On 24 July, in one of the last actions of the campaign on Bougainville, two platoons of the 8th Battalion attacked a Japanese post, Base 5, near Ratsua. Partridge's section came under heavy machine-gun fire and suffered severe casualties, including a Bren gunner who was killed. Although wounded in the arm and leg, Partridge retrieved the Bren gun and began shooting at the nearest bunker while under fire himself. He then rushed forward armed with a grenade and a knife, silenced the Japanese machine-gun with his grenade, and killed the only living occupant of the bunker with his knife. Partridge attacked the second until loss of blood compelled him to halt. Later he re-joined the fight and remained in action while the platoon withdrew.
Partridge was the last and the youngest Australian to be awarded the Victoria Cross in World War II. He was also the first Australian Militiaman to receive the award.