after an initial victory at the Battle of Campichuelo, he was defeated at the Battle of Paraguarí and was forced to retreat. The Junta decided to respond to the reinforcement request from Belgrano, and tasked Azopardo with the transport by river of the reinforcement troops and artillery to Paraguay. The Maltese raised his flag in the "Invencible", while the Frenchman naturalized Argentine Hipólito Bouchard was put in charge of the brigantine "25 de Mayo". Lastly, the sloop "América" was put under the command of the Frenchman Abel Hubac. The royalist authorities in Montevideo learned of these plans and detached a flotilla to intercept the rebels. The mission was given to Jacinto Romarate, an able officer, who could deploy seven small warships of superior quality, and firepower than his enemy's. The Battle of San Nicolás Azopardo's flotilla left Buenos Aires, going upriver on the Paraná. Arriving near San Nicolás they saw the royalists and Azopardo decided to do battle. The rebel commander order a battery of cannons were removed from the ships and installed on the coast, and that a regiment of sailors and militias made ready to fight from the river coast. On 2 March they fought, when the royalist ships closed in the rebels. In the first encounter, two royalist brigantines ("Belén" and "Cisne") became groundned near the coast and were made targets for the coastal cannons and the rebel infantry. Nonetheless, Azopardo could not get to board them and the ships finally freed themselves and retreated. After several hours the royalists tried a new attack, and shot at the "Invencible". The "América" was hit several times, with a gash opening on her prow, beginning to take on water, and had to be abandoned by the crew. The royalists then concentrated on the "25 de Mayo", which they tried to board; the poorly trained crew became panicked and abandoned ship jumping overboard, against the attempts of Bouchard to stop them. The royalist vessels closed in on the "Invencible", which was by now fighting on her own, and boarded her. The crew fought valiantly for almost two hours until the situation became unsustainable. Azopardo tried to blow up the munitions depot, but the wounded begged him not to do it, so he was forced to surrender. Consequences The defeat caused the destruction of the rebel fleet and the taking control over the Rio de la Plata, Paraná and Uruguay rivers