On 11 May, Plagis attempted to down an Italian Reggiane Re.2001 by flying straight at it to ram it; taking erratic evasive manoeuvres, the Italian aircraft stalled and almost crashed into the sea. Thinking he had downed the enemy, Plagis claimed afterwards to have achieved an aerial victory without firing a shot, but the Italian flight reported no losses. Plagis's Spitfire was lightly hit during this engagement, and the Rhodesian had some luck returning safely; he landed with only three gallons (14 litres) of fuel left. On 16 May, Plagis and an English ace, Pilot Officer Peter Nash, destroyed a Bf 109 for a shared kill that became No. 249 Squadron's 100th victory over Malta. Amid the continuing siege, the need for a major supply convoy to Malta was becoming urgent; the Governor Lord Gort warned Britain in early June that if no supplies came by August, he would have to surrender to prevent a famine. Plagis was promoted in the field to flight lieutenant on 4 June 1942 and transferred to No. 185 Squadron to command "B" Flight. He shot down two Re.2001s two days later to bring his tally of victories to ten (thereby fulfilling his pledge following Leggo's death), and destroyed a Bf 109 on 7 June. A month later, he received a Bar to his DFC, having been adjudged to have shown "exceptional skill and gallantry in combat ... Undeterred by superior numbers of attacking aircraft, he presses home his attacks with great determination." Plagis left Malta when his tour expired on 7 July 1942, flying first to Gibraltar, then the UK. The British finally delivered vital supplies to Malta on 15 August with Operation "Pedestal" (known in Malta as the "Santa Marija Convoy"). On arriving in England, Plagis was found to be suffering from malnutrition, scabies and physical and mental fatigue. He briefly convalesced in a nursing home, then spent a year as an instructor in England. He was promoted to probationary flying officer on 1 October 1942. Plagis returned to action in September 1943, when he was appointed commanding officer of No. 64 Squadron, then flying Spitfire Mk VCs over northern France from RAF Coltishall in Norfolk. Plagis downed a Bf 109 over France on 24 September 1943, then a Focke-Wulf Fw 190 on 23 November, and formally received the rank of flight lieutenant on 8 December 1943.