Petrov became commander of the 3rd Squadron of the 68th Fighter Aviation Regiment in the Winter War. He made several victory claims during the war. On 17 February 1940, on Lake Muola-Jarvi, pilot N. Kosichkin was shot down and crash landed on the ice. Petrov landed and strapped Kosichkin to the skis of his I-15bis under Finnish fire. When Petrov landed at his base, there were about 100 holes in the fuselage of his plane. On 7 April 1940, Petrov was awarded the title Hero of the Soviet Union and the Order of Lenin, becoming the first person born in Karelia to receive the distinction.