Dimitri is first seen in the level Vendetta among many wounded Red Army soldiers and is saved from German soldiers executing his remaining comrades by playing dead. Momentarily, he comes acrossSergeant Reznov who also survived the massacre. Petrenko then takes Reznov's Scoped Mosin-Nagant and snipes German sentries under the cover of a bombing raid. After eliminating a German sniper, he and Reznov then meet with elements of the Red Army and provide sniper support for the attacking Russians and then assassinateHeinrich Amsel, a German general responsible for the massacre of Red Army soldiers. Reznov congratulates Dimitri on his marksmanship, only to be attacked by a squad of German soldiers who storm the building they are in. Dimitri then jumps into the river after Reznov to escape the Wehrmacht Soldiers. He and Reznovwould not meet again for three years.
Three years later in the German countryside, Dimitri is captured and taken into a house by 3 German soldiers. While the Germans were conversing and searching Dimitri's dead comrades, Dimitri tries to reach for a fallen comrade's Mosin-Nagantonly to be kicked in the face by a German soldier who shouts "NEIN!" Before they execute him, a T-34 Tank blows a hole in a wall, injuring 2 of the 3 German soldiers. Reznov guns down the last German soldier and orders Chernov, a new recruit, to execute the remaining Nazis. When Chernov refuses since they were already bleeding to death, Petrenko has the option of executing his dying captors himself as he and Reznov have no pity for Wehrmacht soldiers after the atrocities they witnessed in Stalingrad.
After executing or leaving the wounded Germans to die Petrenko joins Reznov for the first time in three years in the final push to Berlin. Upon their reunion, Reznov speaks highly of Dimitri and often tells the other soldiers to follow him as an example, especially to Chernov, who seems to be shocked by the vengeful violence of his comrades against Wehrmacht soldiers. After blowing up German Panzer Tanks, King Tigers and German forces guarding the last defensive line protecting Berlin in a T-34 Tank, Petrenko andReznov join numerous Russian forces in clearing Berlin. During a skirmish in a Berlin subway, however, the tunnel Petrenko, Reznov and Chernov are in is flooded by water, although the three protagonists miraculously survive.
After recovering, Dimitri participates in storming the Reichstag, the seat of the German Parliament and final Nazi stronghold. However at the entrance of the Reichstag, Chernovis incinerated by a flamethrower and falls to the ground coughing and wreathing in pain, forcing another soldier to carry the flag, although he is killed as well during the final stages of the battle, forcing Dimitri to plant the Soviet flag. However, when trying to raise the Soviet flag, a lone remaining Wehrmacht Soldier severely wounds Petrenko by shooting a near-fatal shot at him with a P-38. Before he finishes Petrenko, Reznov charges forward with a machete and repeatedly stabs and slashes the German as he dies. Dimitri then raises the Soviet flag, and the game ends. It is presumed that Petrenko survived the gunshot wound since Reznov said he was going to be alright, as he cheated death numerous times according to Reznov.