After the beginning of Operation Barbarossa on 22 June 1941, Simoniak led the brigade in the defense of Hanko until December, when it was evacuated to Leningrad and subordinated to the Leningrad Front commander. In March the brigade was used to form the 136th Rifle Division, of which Simoniak, then a major general, continued in command of. As part of the 23rd and later the 55th Armies the division fought in the Sinyavino Offensive, in fierce fighting to expand a bridgehead on the eastern bank of the Tosna River. In January 1943 it fought in Operation Iskra a part of the 67th Army, an attempt to relieve the Siege of Leningrad. The 136th launched the main attack of the army on 12 January and at 11:45 on 18 January linked up with elements of the 18th Rifle Division of the 2nd Shock Army to create a corridor to the besieged city. For its actions, the 136th was converted into the 63rd Guards Rifle Division, while Simoniak was made a Hero of the Soviet Union on 10 February.