When the 23rd Panzer Division was formed in September 1941, Boineburg-Lengsfeld was appointed its commander. He was promoted to "generalmajor" shortly afterwards. He led the division during the Battle of the Caucasus but was relieved of command during the "Reichel Case", when plans for Case Blue, the codename for the "Wehrmacht"'s summer offensive in Southern Russia, were lost to the Soviets. However, when his successor as commander, "Generalmajor" Erwin Mack, was killed in action, he returned as the division's permanent leader. In late December 1942, having received a promotion to "generalleutnant" a few weeks earlier, he was injured as a result of an accident with a tank. With several broken bones, he underwent an extended period in hospital.