In August 2014 the brigade's units fought in the Battle of Ilovaisk. On 29 August, during a Ukrainian breakthrough attempt from Ilovaisk, a "northern" column of Ukrainian forces took the fight with 21st brigade's troops on a road between Voznesenka and Horbatenko villages. Ukrainian T-64 tank and several BMP-2s of 51st Mechanized Brigade were able to destroy two T-72BA tanks and a BMP-2 of the 21st Motor Rifle Brigade. Another 21st brigade's T-72BA tank was destroyed near Kumachove village, presumably by a Tochka-U missile strike of the 19th Missile Brigade.