After several weeks, the expedition was reinforced by another party of Filipino and Spaniards under the command of Don Pedro Fernandez del Rio. The lake region was explored and alliances were formed with various Maranaw datus.
After completing their mission, Father San Pedro retired to his convent in Butuan while Captain Atienza returned to his post in Caraga.
The following year (1640) another Spanish expedition of 500 Bohol Filipinos and 50 Spaniards, under Don Pedro Bernandez de Castro, went to Lake Lanao to establish Spanish sovereignty. This time the liberty-loving Maranaw, roused by this threat of Spanish imperialism attacked the expedition. The invaders were hard-pressed and faced annihilation.
Fortunately for them, a relief party led by Father San Pedro arrived in time and rescued them from Moro. The embattled survivors were brought back by the gallant padre to Iligan. For more than 250 years after this fiasco, no Spanish expedition attempted to invade Lake Lanao.