On 21 September, during the Battle of the Niemen River, he was given urgent orders to depart to and take up defensive position along the Neman River. At the time, the battalion had 500 men and only 5 officers and no telephones. In Hoža, Vitkauskas learned that Lithuanian forces moved to Druskininkai where Polish forces concentrated their attack. Vitkauskas contacted the commander of Russian forces in Grodno who promised to send 48th and 49th Infantry Regiments but they never showed. Polish forces took Druskininkai and began their advance towards Hoža. Vitkauskas ordered a retreat to , a railway station on the Saint Petersburg–Warsaw Railway, but Polish forces got there first. The battalion was cut off from other Lithuanian units. Vitkauskas then decided to march back to . The next day they marched to but it was also taken by the Polish Army. The battalion turned to Vasilishki and pushed to Lida where it found some men from the 1st Battalion of the 7th Infantry Regiment. Vitkauskas managed to get permission from the Russian commander to gather the men and continue to Ashmyany which they reached on 30 September 1919. From there, they turned to Vilnius and reunited with Lithuanian forces. In total, to escape the encirclement and capture, Vitkauskas led some 750 men who marched in 7 days in very difficult circumstances due to lack of food for the men and feed for the horses.