The Romanian General Headquarters together with the Russian High Command on the Moldavian Front had drawn up an offensive plan, which called for a double strike: one in the Marasti area and the other on the lower part of the Sereth River, in the Namoloasa area. It was hoped that this way the German 9th Army would be encircled and destroyed and then the advance could continue towards Ramnicu Sarat.
The offensive in the Soveja Basin, which would later be known as teh battle of Marasti, was going to be carried out by the Romanian 2nd Army, commanded by lt. gen. Alexandru Averescu. He had at his disposal to corps, made up of four infantry divisions and a cavalry brigade. In total 56 infantry battalions and 14 cavalry squadrons supported by 228 artillery pieces (of which 52 heavy artillery) and 21 aircraft. The main strike was going to be concentrated on a 35 km wide area.
Opposite the Romanian forces was the Gerock Group, the right wing of the Austro-Hungarian 1st Army, made up of 21 infantry battalions and 36 cavalry squadrons, supported by 142 artillery pieces (of which only 6 were heavy artillery). Although he was in numerical inferiority, the geographic position offered the Austro-Hungarian commander a lost of defensive solutions. Several strongpoints were organized, linked by trenches and positioned so that they could support each other. The main positions were on the Casin and Teius Hills, in the Incarcatoarea Meadow and the Marasti village.
After a thorough reconnaissance, general Averescu decided to brake the front on the left of the 2nd Army, on a 13 km wide area, between the Incarcatoarea Meadow and Marasti, because the terrain was more favorable there. This task was given to the 2nd Corps, commanded by maj. gen. Artur Vaitoianu, to which the 3rd Infantry Division and the 6th Infantry Division (minus one brigade) as well as the army's entire heavy artillery were subordinated. On the right wing, the 4th Corps of general Valeanu was made up of the brigade taken form the 6th Infantry Division and the 8th Infantry Division. It had the mission to pin down the Central Powers forces in front of it and if the 2nd Corps made any progress, it was also supposed to advance. The 1st Infantry Division, minus its artillery, which had been temporarily assigned to the 2nd Corps, was the army's reserve.
The artillery preparation began in the morning of 22 July 1917 and lasted until the evening of the following day. The bombardment had managed to disorganize the German fortifications and make 12 breaches in the barbwire nets, thus general Averescu decided to attack on 24 July.
At 0345 hours, the Romanian infantry had quietly advanced up t o150 m from the positions of the German 218th Infantry Division. After a 15 minute long artillery preparation, the 3rd Infantry Division of maj. gen. Alexandru Margineanu attacked.. The 24th Infantry Regiment Tecuci assaulted the Incarcatoarea Meadow and managed to occupy the first trenches, but a powerful counterattack in the evening pushed it back to its started positions. The 2nd Vanatori Regiment and the 4th Dorobanti Regiment Arges managed to take Marasti Hill, thus making the first breach in the front of the German 218th Infantry Division. They continued the advance and attacked the positions on Teius Hill and occupied it. The troops in the Incarcatoarea Meadow were threatened to be encircled and had to retreat. For this action, the two commanders: lt. col. Constantin Calotescu (4th Dorobanti Regiment) si lt. col. Mihail Butescu (2nd Vanatori Regiment) were awarded the Mihai Viteazul Order 3rd class.
The 22nd Infantry Regiment Dambovita received the mission to assault the Marasti village. The CO decided to pin down the German troops with two companies and with two battalions to attack from the heights north of the village. The maneuver was successful and forced the enemy to retreat. The 30th Dorobanti Regiment Muscel attempted to take the Manastioara Hill, but all its assaults failed. After the 22nd Regiment took Marasti, it continued the advance and arrived behind the German positions on the Manastioara Hill. The combined attack of the two regiments eventually led capture of the fortifications and of the garrison's remains. The company commanded by lt. Stefan Chiritescu, from 30th Dorobanti Regiment, infiltrated southwards and took 2 officers and 150 soldiers prisoners. Lt. Chiritescu received the Mihai Viteazul Order 3rd class.
In the first day of the offensive, the Romanian troops had created a 10 km wide breach in the front of the German 218th Infantry Division, taking 1,500 POWs. The Russian 15th Infantry Division (from the Russian 4th Army), deployed on the left flank of the 2nd Army, occupied Momaia Hill, where it captured 500 soldiers.
The defeat created a powerful impression in the Central Powers command, which decided to strengthen the 1st Austro-Hungarian Army. General Gerock organized a new defence line on the Tehereale HIll, Rachitasul Mare and Teius Hill, which offeed him a dominant position over the Vrancea Depression.
General Averescu wanted to exploit the intial success as much as he could, so he introduced in the first line the 1st Infantry Division of brig. gen. Dumitru Stratilescu and brought the cavalry brigade closer to the infantry, to make it easier to infiltrate behind enemy front, should there be such an occasion.
The following day, the 6th Infantry Division, commanded by brig. gen. Nicolae Anghirescu, attacked and took Incarcatoarea Meadow. On 26 July he continued the advance assaulting enemy positions on the Tehereale Hill, which capitulated after a combined action with the 8th Infantry Division.
The 1st Infantry Division had the task to take the Rachitasul Mare, a peak 927 m high. It had a powerful heavy artillery support and several small units infiltrated behind the front. These made it possible for general Stratilescu to fulfill his mission and occupy the heights.
The 3rd Infantry Division assaulted the Teius Hill. The 22nd Infantry Regiment was met by very stiff resistance, in some cases there were even hand–to-hand combat situations. Lt. col. Butescu managed to sneak with the 2nd Vanatori Regiment through an unguarded valley and arrived behind the German 218th Infantry Division. The Teius Hill was surrounded and eventually fell into Romanian hands. Thus the 2nd Army made a 30 km wide breach in the front of the Gerock Group, which started to fall back. The Romanian troops reoccupied Soveja and cut the retreat path of the Austro-Hungarian 1st Cavalry Division.
But the success of the Central Powers offensive in Galicia determined the Romanian General Headquarters to stop the advance of the 2nd Army. General Averescu requested to be allowed to at least reoccupy the entire Vrancea Depression. Thus, on 27 July, the attacked restarted along the entire front.
The 8th Infantry Division took the Arsita Mocanului Peak and the 6th Infantry Division pushed back the Austro-Hungarian 1st Cavalry Division and captured the Cocosila Peak. In the sector of the 1st Infantry Division, the 18th Dorobanti Regiment Gorj infiltrated between the German 218th Infantry Division and the Austro-Hungarian 1st Cavalry Division, threatening their flanks. These had to retreat towards Lepsa. The Romanians occupied the Roschila Peak. The 1st Vanatori Regiment reached the Putna River. The 3rd Infantry Division continued also the attack. The 22nd Infantry Regiment and 2nd Vanatori Regiment took the Topesti and Valea Sarii villages, pushing the Germans over the river.
The Gerock Group received reinforcements consisting of two infantry divisions (37th and 117th) and two cavalry divisions (7th and 8th) and, to the south, the German 9th Army strengthened its left wing with 3 divisions (76th, 212th and 216th Infantry).
On 28 July the 2nd Army however managed to fulfill its mission. The 3rd Infantry Division reached the Putna River, eliminating the last resistances on the left bank and created several bridgeheads over it. The 7th Vanatori Regiment from the 6th Infantry Division took the Zobina Neagra Peak. Only the 8th Infantry Division was stopped by the Austro-Hungarian 8th Mountain Brigade, in the Casin Hill sector. General Averescu asked for support from the Russian 9th Army, which had to infiltrate a assault battalion behind the Austro-Hungarian lines and to attack the hill from behind… General Patrascu, the Romanian division's commander, decided to pin down the enemy with a part of his forces and with the other, led by col. Liciu, to outflank the Austro-Hungarians on the right. The plan failed, as the mountain troops put up a serious fight. The Russian battalion did not attack as planned, but retreated, endangering the flank of te h8th Division. The fighting continued the following days and, on 30 July, col. Liciu managed to take Razboiului Peak, south of Casin hill.
On 1 August lt. gen. Alexandru Averescu decided to stop the offensive also in the sector of the 8th Infantry Division, because he thought the position it now occupied was satisfactory. Thus the battle of Marasti was over. The 2nd Army had managed to create a bulge 30 km wide and 20 km deep in the front of the Austro-Hungarian 1st Army and determined the Central Powers to change their operations plan and bring reinforcements to the area. Over 2,000 POWs were taken and 70 artillery pieces were captured. The Romanian troops lost about 4,500 men (1,500 dead and 3,000 wounded). No less than 32 Mihai Viteazul Orders 3rd class were awarded to the Romanian officers and the flags of four regiments (5thm 18th and 30th Infantry and 2nd Vanatori), which had captured in total 1,637 POWs, also received the order. Lt. general Averescu got the Mihai Viteazul Order 2nd class..