 North of Lake Ladoga on the Ladoga Karelia front , the defending Finnish units relied on the terrain . Ladoga Karelia , as a large forest wilderness , did not have road networks for the modern Red Army . However , the Soviet 8th Army had extended a new railroad line to the border , which could double the supply capability on the front . But on 12 December , the advancing Soviet 139th Rifle Division , supported by the 56th Rifle Division , was defeated by a much smaller Finnish force under Paavo <unk> in Tolvajärvi , the first Finnish victory of the war . 
