After the Treaty of Paucarpata had been repudiated, the Chilean government again dispatched its fleet of 5 battleships (Aquiles and Arequipeño, the corvettes Libertad and Valparaíso and the Monteagudo) under the command of Roberto Simpson, to disrupt Peruvian commerce.

On January 12, 1838, the Chilean squadron surprised the Confederates in Islay, which largely surpassed in tonnage and fire hydrants fled to the north being persecuted by Simpson.

The pursuit lasted all night and turned the Confederate ships to shoot the corvette Libertad, whose greater speed had allowed it to overtake the rest of its squad to continue the flight.

Before that situation, Panizo used a clever stratagem by turning around, and the Socabaya and the Founder broke fire on the Chilean ships, which delayed them and allowed the Junin to gain distance.

Three times, he performed the same maneuver until the Junín was out of danger, and the darkness of the night made Simpson order to stop the pursuit, and he continued to Callao, where he arrived on January 17.