In the Battle of Pákozd he covered the wing of the Hungarian army south of Lake Velence.

During the army's withdrawal he received a letter from Lajos Kossuth and decided to fight against the Emperor.

Arrest warrants were issued by the Austrian government for Kossuth, Perczel and General Josef Bem.

Then he marched with his army to Novi Sad which is directly opposite Petrovaradin on the Danube River.

[5] Then Perczel made contact with the Hungarians besieged in Petrovaradin fortress and established his center of operations there.

[6] Together with Count Lajos Batthyany, former Prime Minister of the new Hungarian Republic, but since 15 September 1848 a general in the Hungarian Army, Perczel move the main body Hungary military forces against Danube and the Drava Rivers to threaten Slavonia and to restrict Austrian navigation between Pest and Mohács.

The maneuver had the additional effect of sending the Austrians on the western front retreating back toward Zagreb in southwestern Hungary and Osijek.

[8] Marching back across the Banat toward the Theiss River, Perczel's army was stopped pushed into retreat by Serbian forces under Georg Stratimirovich, and Kusman von Todorovich.

Because of the defeat the government relieved him and gave an order to set up and lead the reserve army.

When the government and the leading generals met, Perczel criticised the leadership, especially Lajos Kossuth.