According to historian Digby Smith, Knežević was promoted to General-major on 29 October 1800. However, another source shows that he commanded a brigade with the rank of General-major in Konrad Valentin von Kaim's 4,939-man division at the Battle of Marengo on 14 June 1800. His command included three battalions of the Infantry Regiment "Grand Duke of Tuscany" Nr. 23, a total of 2.188 soldiers. During the late morning, Kaim's division repeatedly attacked the French line behind Fontanone Creek with little success. Later in the day, all three brigades of Kaim's division joined the pursuit under Anton von Zach and were involved in the rout of the main column at the end of the battle.