Between 25 January and 13 February 1915, the army fought in the Second Battle of the Masurian Lakes, during which the German 8th and 10th Armies were to encircle and destroy the 10th Army by attacking it from the flanks. The German 8th Army struck the 10th Army's left towards Augustow on 25 January, while the German 10th Army attacked on the right towards Verzhbolovo and Suwałki between 26 and 30 January. In intense defensive fighting, the troops of the 10th Army held back the German advance for ten days, enabling the main Russian forces to retreat to the Kovno and Osovets line by 13 February. The army rebuffed another unsuccessful German encirclement attempt during the Battle of Przasnysz between 7 February and 17 March. On 17 February, the 10th Army, in concert with the 1st and 12th Armies, launched a counteroffensive and pushed the German troops back to the East Prussian border, overcoming fierce resistance. Sievers was replaced by General of infantry Yevgeny Radkovich on 25 April.