President Francisco Solano López decided to attack the Allied supply bases at Tuyutí and Itapirú on the Paraná river.

The Paraguayan infantry were to attack from the east (from the area of Paso Yataytí Corá) in three columns at 04:30 on November 3.

The cavalry was to make a wide sweep to the port of Itapirú and then charge the Allied rear.

The Paraguayan infantry quickly took the outer Allied entrenchments and pushed back the second line into the supply camp.

The Paraguayans set about pillaging when they were attacked in the supply camp by an Allied artillery redoubt under the command of general Porto Alegre, which consisted of 1,800 men and 14 guns.