 Johnson's last certain victories of the year were achieved on 21 September 1941. Escorting Bristol Blenheims to Gosnay, the top cover wings failed to rendezvous with the bombers. Near Le Touquet at 15: 15 and around 20,000 feet, Johnson's section was bounced by 30 Bf 109s. Johnson broke and turned in and behind a Bf 109F. Approaching from a quarter astern and slightly below, Johnson fired closing from 200 to 70 yards. Pilot Officer Smith of Johnson's section observed the pilot bail out. Pursued by several enemy aircraft, Johnson dived to ground level. About 10 miles off Le Touquet, other Bf 109s attacked. Allowing the Germans to close within range, Johnson turned into a steep left-hand turn. It took him onto the tail of a Bf 109. Johnson fired and broke away at 50 yards. The Bf 109 was hit, stalled and crashed into the sea. Johnson was pursued until 10 miles south of Dover. The two victories made Johnson's total to six destroyed, which now meant he was an official flying ace. In winter 1941, Johnson and 616 Squadron moved to training duties. The odd convoy patrol was flown but it was an idle period for the Squadron which had now concluded its "Tangmere tour".
