This ill-judged delay was of great importance to the inhabitants of St Jago, by giving them time to prepare for their defence.  They could not at first believe it possible that Lautaro would have the audacity to undertake a march of three hundred miles beyond the Araucanian frontiers to attack their city; but undeceived by the refugees from Conception, and the daily reports of the ravages of the enemy in the territories of the Promaucians, they dispatched Juan Godinez with an escort of twenty-five horse into the Promaucian country to watch the motions of the enemy, and to send intelligence of his proceedings and designs.  Godinez was unexpectedly attacked by a detachment of the Araucanians, and obliged to make a precipitate retreat to St Jago, with his numbers considerably diminished, and filled the capital with consternation and dismay at the intelligence of the near approach of their redoubted enemy.  On this occasion the Araucanians took ten horses and some arms from the Spaniards, both of which were used by them in the succeeding actions.

Villagran, who was at this time unable to take the field in consequence of illness, sent his son Pedro against Lautaro with such troops as could be procured, and immediately proceeded to fortify all the approaches to the city of St Jago with strong entrenchments.  In the mean time, young Villagran attacked the Araucanians in their fortified post.  Instructed by their intrepid yet wary commander, the Araucanians pretended to take flight after a short resistance; but the Spaniards were no sooner entered into the abandoned inclosure, than they returned upon them with such impetuosity, that Pedro and his men were completely routed, and only the cavalry was able to escape by flight, all the infantry who had penetrated the Araucanian camp being put to death.  After procuring reinforcements, young Villagran returned three several times to attack the camp of Lautaro, in all of which attempts he was repulsed with considerable loss.  He now encamped his force in a low meadow on the banks of the river Mataquito, at no great distance from the entrenched post of Lautaro.  The Araucanian general formed a plan for inundating the camp of the Spaniards during night, by turning upon them a branch of the river; but the Spaniards being informed of this design by a spy, withdrew to St Jago.

Having recovered from his illness, Villagran was solicited by the citizens of St Jago to exert himself to dislodge the Araucanians from their neighbourhood, as they every moment expected to see them at their gates.  He accordingly, some time in the year 1556, set out from the city at the head of 196 Spaniards and 1000 Indian auxiliaries, in search of Lautaro.  Instructed by his severe defeat at Mariguenu, Villagran resolved to attack the enemy by surprise; and quitting the direct road, he secretly directed his march towards the Araucanian encampment in the night by a private path under the guidance of a spy, and reached their entrenchments