He was actively participating in the actions at the village of Morachwa, the Valowka, Lyubor, Zieleńce, Horodnica, where he was awarded once again with the Order of St. Vladimir, 4th degree.

Denisov survived and received the Prussian Order of Pour le Mérite for another action on 26 June at Lipovoye Pole, where the Polish detachment of Colonel Dobiek was defeated.

On 10 October, he took part in the battle of Maciejowice, in which, commanding Cossack regiments, completely defeated the Polish cavalry, crashed into the infantry and pursued his fleeing enemy until Kościuszko was taken prisoner.

Then, Denisov participated in the affair at Lecco, in the battle on the river Adda, where he crushed the French with a flank attack and rescued the Austrians surrounded by the enemy.

Further, together with Suvorov, Denisov made the crossing of the Alps, where in the battle of the Muottental, he was the first to snuck in from the left flank of his enemy through the mountains covered with woods, and at a great distance without stopping chased the French.

Having formed 11 regiments, Denisov crossed the Volga with them, but, reaching the Irgiz river, received news of the death of Emperor Paul I and the order to return to the Don.

In 1807, at his own request, he was appointed to the active army in Prussia, where he took command of 3 regiments and participated in the battles of Guttstadt, Passarg, Semersfeld, Arensdorf and Heilsberg.