After VVKJ acceptance, a group of pilots conducted 16 mock dogfights between the IK-2 and the Hawker Fury I biplane already in service with the VVKJ, during which the IK-2 displayed overall superiority over the British-built aircraft. At one point, Bajdak declared his continuing doubts about the aircraft, and Dobnikar challenged him to a duel, with Bajdak flying his preferred aircraft, the Fury I. After Dobnikar won the climbing competition and a race to Zemun and back from Belgrade, the final dogfight forced Bajdak to concede that the IK-2 was the better aircraft. On 20 November 1937, the VVKJ submitted a proposal to order a batch of 12 IK-2s, which was approved the following month. The production version included some additional improvements, but continued testing resulted in further delays, with the aircraft not entering service for another year. By this time, international consensus had coalesced around the superiority of the low-wing monoplane, and the IK-2 was already obsolescent by the time it was delivered to VVKJ fighter units.