After Dagobert von Wurmser's defeat at the Battle of Bassano on 8 September, Ott led the Austrian advance guard with great distinction during Wurmser's dash to Mantua. At Cerea, he held off a French intercepting column long enough for Wurmser to arrive and defeat it. The next day, Ott ambushed the 12th Light Demi-Brigade, killing its commander, Brigadier General Charles-François Charton and capturing 400 men. During the battle under the walls of Mantua on 15 September, he commanded the left flank at La Favorita. His force was the last part of the Austrian army to retreat. He led a sortie on 23 September which suffered heavy losses at Governolo. In February 1797, he surrendered with the garrison at the unsuccessful conclusion of the Siege of Mantua. On 1 March 1797, Emperor Francis II appointed Ott Feldmarschal-Leutnant.