From 1943 to 1945, he served in the 3rd SS-Brigade and the 20th Waffen Grenadier Division of the SS. He was the Commander of the 45th SS-Grenadier Regiment from April 1944. On 23 August 1944 he was decorated with the Knight's Cross of the Iron Cross for his actions in the Battle of Tannenberg Line and in the Battle of Auvere where Riipalu and his regiment drove back the assault of the Soviet Army, which prevented the encirclement of Army Detachment Narwa. The award was presented to him by Felix Steiner, the commander of III SS Panzer Corps.