In 1627 Montoya was made head of the missions in Guayrá, which opened up to him the opportunity of showing what kind of man he was. In this year the Spaniards of Villa Rica, the nearest town in Paraguay to the reductions in Guayrá, sent out an expedition to chastize some Indians who had insulted a chief called Tayaoba, whom Montoya had baptized. This was the pretext for the expedition, but Montoya knew well that the real object was to hunt for slaves. He brought before the Governor the edict of the King of Spain forbidding any war to be made upon the Indians without sufficient cause. All was in vain, and the expedition left Villa Rica and plunged into the wilds. Montoya, sore against the Governor’s desire, went with the expedition, taking with him Padre Salazar and some well-armed Indians. It was lucky for the Spaniards that he was there, for on the second day a flight of arrows burst from a wood and wounded many of them. The captain of the expedition ordered a retreat, which, situated as they were, exposed on all sides to the fire of an enemy whom they could not see, must have proved fatal. Montoya counselled throwing up earthworks before some huts which stood upon the edge of the woods in which the Indians were; this done, he sent a messenger to Villa Rica for reinforcements. Even behind the earthworks the Spaniards were hard pressed; no one could show himself without being pierced by an arrow. The number of the Indians daily increased, till on the third day they numbered about four thousand, and seemed likely to advance upon the huts. The Spanish captain ordered a rally, and the neophytes wished to decamp, taking Montoya with them, and then gain the shelter of the woods. This he would not allow, and, charging with the soldiers, put the Indians to flight. The Spaniards, far from being grateful for their lives, seeing their hopes of making prisoners had vanished, wished to lay hands upon the Indians whom Montoya had brought, and who had fought beside them in the recent fray. Hearing that in the morning the Spanish soldiers would attack his neophytes, Montoya sent them off by night, and in the morning, when the Spanish captain found him and the other priest alone, he said, ‘Thinking you had no other use for the Indians, I advised them to return.’ The captain had the grace to say nothing but, ‘Then, you gave them good advice, my father.’ The two priests waited patiently till the soldiers had retired, and then sent for their Indians and quietly went home. Thus it appears that at necessity Padre Montoya was a true son of San Ignacio.