After losing some hours in an attempt to fix it, it was decided to continue with only the remaining 8 steamers. The fleet arrived at Corrientes after sunrise, however, due to a dense fog, the plan was still executable since most, if not all, Brazilian forces were still on land. However, not following López' orders, Captain Meza ordered that instead of approaching and boarding the docked steamers, the fleet was to continue down the river and fire at the camp and docked vessels as they passed by. The Paraguayans opened fire at 9:25 am. The Paraguayans passed in a line parallel to the Brazilian fleet and continued downstream. Upon Captain Meza's order, the entire fleet opened fire on the docked Brazilian steamers. The land troops hastily, upon realization that they were under attack, boarded their own ships and began returning fire. One of the Paraguayan steamers was hit in the boiler and one of the "chatas" (barges) was damaged as well. Once out of range, they turned upstream and anchored the barges, forming a line in a very narrow part of the river. This was intended to trap the Brazilian fleet. Admiral Barroso noticed the Paraguayan tactic and turned down the stream to go after the Paraguayans. However, the Paraguayans started to fire from the shore into the lead ship, "Belmonte". The second ship in the line, "Jequitinhonha", mistakenly turned upstream and was followed by the whole fleet, thus leaving "Belmonte" alone to receive the full firepower of the Paraguayan fleet, which soon put it out of action. "Jequitinhonha" ran aground after the turn, becoming an easy prey for the Paraguayans. Admiral Barroso, on board the steamer "Amazonas", trying to avoid chaos and reorganize the Brazilian fleet, decided to lead the fleet downstream again and fight the Paraguayans in order to prevent their escape, rather than save "Amazonas". Four steamers ("Beberibe", "Iguatemi", "Mearim" and "Araguari") followed "Amazonas". The Paraguayan admiral (Meza) left his position and attacked the Brazilian line, sending three ships after "Araguari". "Parnaíba" remained near "Jequitinhonha" and was also attacked by three ships that were trying to board it. The Brazilian line was effectively cut in two.