During the war he completed 457 sorties, in which he gained at least 31 individual kills, making him one of the highest-scoring Soviet flying aces.

Klubov and several of his colleagues were then assigned to the 1st squadron and underwent training under the supervision of Aleksandr Pokryshkin, one of the highest-scoring aces of the Soviet Union.

[2][4] On 4 September 1943 Klubov was nominated for the title Hero of the Soviet Union for having completed 310 sorties, engaged in 84 dogfights, and personally shot down 14 enemy planes.

He was detained and sent to be tried by a military tribunal, which likely would have resulted in him being sent to an infantry penal battalion with a high mortality rate, but Aleksandr Pokryshkin intervened and requested a more lenient sentence, insisting that losing a flying ace to a penal battalion would be result in many additional losses of Soviet aircraft.

Throughout the war he scored 31 solo victories, gained three shared shootdowns, flew 457 sorties, and engaged in 109 aerial battles.