In Los Infantes captain Lorenzo Bernal del Mercado had discovered that the rebels had constructed a pukara close by, establishing a blockade of the city, additionally natives under the toquiIllangulién had chosen an impregnable position in a marsh. A Mapuche detachment located themselves in a third position awaiting reinforcements from their main body at the old position. Seeing that this position was weak the Spanish engaged this position. In the battle the Spanish drove the Mapuche out of their pukara and pursued them down to the river bank and drove them into the river, where they were trapped and 1,000 Mapuches were killed, including the toqui Illanguelén.
^Lobera, Crónica del Reino de Chile, Capítulo XXII