Murphy participated in the September 1943 mainland Salerno landing at Battipaglia. While on a scouting party along the Volturno River, he and two other soldiers were ambushed; German machine gun fire killed one soldier. Murphy and the other survivor responded by killing five Germans with hand grenades and machine gun fire. While taking part in the October Allied assault on the Volturno Line, near Mignano Monte Lungo Hill 193, he and his company repelled an attack by seven German soldiers, killing three and taking four prisoner. Murphy was promoted to sergeant on 13 December.