There were actually two separate revolutions that made up the Russian Revolution. The first involved the overthrow of the monarchy and the installation of a new provisional government. The Bolshevik Revolution was led by Lenin, and involved the overthrow of that newly installed provisional government and the creation of a Marxist state. Probably the fatal mistake that facilitated the Bolsheviks' success was the new government's decision to remain in World War I, an opportunity the Bolsheviks seized on as they launched their coup d'état.
Once in control of the government, the Bolsheviks negotiated for a peaceful settlement with Germany, ultimately agreeing to the Treaty of Brest-Litovsk in 1918 (with significant territorial concessions). With the eastern front closed, Germany could now pour all of its attention towards the western front, attempting one last push to win the war. By this point, however, the momentum had already begun to turn against Germany, with the intervention of the United States in 1917 and the influx of US manpower and resources to the Allies, not to mention new technological innovations such as the tank. The war would end in November of 1918, with Germany's surrender to the allies. In the meanwhile, Russia would continue on its course through a long history of internal turmoil, in the grips of civil war.
In this respect, I think there's a strong argument that Russia's surrender in World War I came too late where the Central Powers were concerned. By this point in time, the decisive turning points had already arrived, with the conditions of the war weighing more and more heavily in the Allies' favor.