On the night of 10 December, the 718th Rifle Regiment of the Soviet army swung around the Finnish rear of the Tolvajärvi front and attacked the lightly defended Finnish supply and artillery troops at Varolampi Pond[3] situated along the Korpiselkä [fi]-Tolvajärvi road.

The surprise attack saw initial success by the Soviet troops in advancing through the Finnish lines but soon faltered.

The Soviet soldiers stopped to eat the sausage soup that the retreating Finns had left behind in their field kitchen.

This gave enough time for Major Pajari, who happened to passing nearby at the time, to muster men from the 16th Infantry Regiment (JR 16) Headquarters Company, and Third Battalion supply elements, which included field cooks, clerks, supply and artillery NCOs, to launch a counter-attack, accompanied by the battle cry Hakkaa päälle.

By dawn on 11 December the counter-attack succeeded in driving back the Soviet force and inflicted heavy casualties, with over 100 dead Soviet troops left on the field according to Finnish estimates, along with 20 dead on the Finnish side.