On 9 August 1918 at Rosières, east of Amiens, on the second day of the Battle of Amiens, Beatham's battalion was attacking high ground when it was held up by heavy machine gun fire after supporting armour was knocked out of action. Beatham, accompanied by Lance Corporal W. G. Nottingham, made four charges to knock out a series of German machine gun posts holding back the advance of the Australians. Wounded in the leg during the first charge, he was killed taking out a final machine gun post on 11 August. For his gallantry he was posthumously awarded the Victoria Cross (VC). Gazetted on 14 December 1918, the citation for his VC read as follows:
For most conspicuous bravery and self-sacrifice during the attack north of Rosieres, east of Amiens, on 9th Aug., 1918. When the advance was held up by heavy machine gun fire, Pte. Beatham dashed forward, and, assisted by one man, bombed and fought the crews of four enemy machine guns, killing ten of them and capturing ten others, thus facilitating the advance and saving many casualties. When the final objective was reached, although previously wounded, he again dashed forward and bombed a machine gun, being riddled with bullets and killed in doing so. The valour displayed by this gallant soldier inspired all ranks in a wonderful manner.
— The London Gazette, 14 December 1918