From that point the army moved to Candelaria, which was used as a stronghold for the attack into Paraguay. The terrain gave a clear advantage to the Paraguayan governor Velazco against Belgrano: the Paraná River, nearly wide, was an effective natural barrier, and once it was crossed the patriotic army would have to move a long distance across a land without supplies. Swamps, hills, rivers, and lakes would force the army to march slowly, making a possible retreat very difficult. The Parana was crossed with several boats on 19 December, and a task force of 54 Paraguayan soldiers was forced to flee during the Battle of Campichuelo. Belgrano saw Velazco's army from the Mbaé hill, and despite being greatly outnumbered, he ordered an attack, trusting in the moral strength of his soldiers. When the Battle of Paraguarí started, the patriots briefly held the upper hand, but eventually Velazco, with superior numbers, prevailed. Even with 10 deaths and 120 soldiers taken prisoner, Belgrano wanted to continue the fight, but his officials convinced him to retreat.