Following their failure to break through the Carpathians in October, the Central Powers reconsidered their options and adopted a new plan. Now Romania was to be invaded from three distinct directions : to the south, new German forces poured into Bulgarian to form the Danube Army, together with Bulgarian and Turkish forces withdrawn from Dobrogea. This army ( known as "Group Kosch" ) crossed the Danube on the 11th of November virtually unopposed and proceeded north towards Bucharest. To the west, more German troops rushed in to save the situation in the Jiu area. After concentrating 5 infantry and 2 cavalry divisions, the enemy attacked all along the frontline. Overwhelmed by the vastly superior German forces ( the ratio was 7/1 or worse in the main attack sector ) the Romanians were defeated and forced to give ground. "Group Kuhne", as this force was designated, was then finally able to push deep into western Romania and menace Bucharest itself. In the end, Austro-Hungarian and German units in the north also resumed their attacks and eventually captured the passes at the cost of very heavy casualties.

On the 15th of November 1916, Prezan chose his opponent. His main blow would fall upon the Kosch group to the south, which he hoped to encircle and destroy by hitting the center and right flank. To achieve numerical superiority, the 2/5 division and a cavalry brigade were taken from the 1st Army. This decision created a gap between the 1st Army and the "Defense of the Danube" group, a gap towards which was heading the Kuhne group from the west. Prezan relied on the Russians for filling this gap in time, but in the end he was proven wrong as in spite of a promise coming straight from the tzar of Russia, the allies would not arrive in time.

Two days later, the Romanians launched their attack, just as in the north the Kraft group infiltrated with its elite Alpine Corps through another gap, this time betwenn the Romanian 1st and 2nd armies. For three days, the Romanian divisions fought their way southwards, smashing through the lines of the German and Bulgarian forces. Actually, by the 19th of November, the German 217th Infantry Division was in a desperate situation : outflanked by the Romanian 9/19 and 2/5 divisions and attacked frontally by the 21st, it had been all but cut off. 2500 Germans had been captured with over 5000 others killed, but the division's commander pleas for help fell on death years. Falkenhayn seemed too busy to launch its final thrust towards Bucharest to notice the dangerous situation in the south. At that time however, the Germans had a stroke of luck, as they captured the Romanian battle plan. Descovering now the gaps in the Romanian lines, gaps which the Russians had failed to seal, Falkenhayn threw his Kuhne and Kraft groups into the breaches, threatening the rear and left flank of the large Romanian force in the south. In the end, the Romanian Supreme HQ had to abandon its plans of a decisive battles and order the withdrawal of the army into eastern Romania, after the few Russian reinforcements that did arrive showed little will of fighting. This meant abandoning the entire central and western Romania to the Central Powers. Several German attempts to overrun the rest of Romania were easily repulsed and by the 28th of December 1916, both sides dug in on a line stretching from the start of Carpathian mountains in the north to the rivers Putna and Siret in the south. The decisive battles would be fought in the summer of 1917...