With these aircraft GC III/3 fought in the Battle of France. Stehlik he shot down four enemy aircraft solo and shared in shooting down four others. On 22 June 1940 France capitulated to Germany. Stehlík and other Czechoslovak airmen were evacuated to the United Kingdom, where they were quickly enlisted in the RAF Volunteer Reserve. Stehlík was re-trained to fly Hurricane Mk I fighter and given the rank of sergeant. He was posted to the newly-formed No. 312 (Czechoslovak) Squadron RAF, where he was allocated to Yellow Flight with Pilot Officer Alois Vašátko and led by Flight Lieutenant Denys Gillam. By October 1940 the squadron was stationed at RAF Speke outside Liverpool. About 16:00 hrs on 8 October a lone "Luftwaffe" Junkers Ju 88 medium bomber of "Kampfgeschwader 2/806" was sighted flying up the River Mersey. Yellow Flight was scrambled, with Stehlík flying Hurricane L1807. All three fighters machine-gunned the Ju 88, killing its observer and setting fire to its two engines. At 16:15 the bomber made a forced landing in a field near Bromborough Dock and the surviving crew were captured. On 14 March 1941 Stehlík shot down a Ju 88 over the sea. In raids over German-occupied France he damaged a Messerschmitt Bf 109 fighter and on 10 July 1941 probably shot down a Bf 109. In October 1941 Stehlík was transferred from operation flying and trained at RAF Upavon to become a flying instructor. He was then posted to RAF Hullavington as an instructor. From January 1942 until February 1943 he served at Elementary and Secondary Flying Training Schools in Canada. In April 1943 Stehlík returned to 312 Squadron, which had been re-equipped with the Supermarine Spitfire Mk VC. With 312 Squadron he flew several raids over occupied Europe. Early in 1944 Stehlík joined the 1st Czechoslovak independent fighter aviation regiment in the Soviet Union. He was commissioned as a "nadporuchik" (senior lieutenant) and commanded the regiment's 1st Squadron. From 15 September 1944 Stehlík was based at Tri Duby airfield in central Slovakia, fighting in the Slovak National Uprising. Flying a Soviet-built Lavochkin La-5FN fighter he shot down a Ju 88 on 19 September and shared in shooting down a Junkers Ju 87 ground-attack aircraft on 7 October.