On September 6, 1879 Latorre was promoted to commander of the ironclad Cochrane, the strongest unit of the Chilean fleet.
His fame was such that he brought his entire crew with him.
His first mission was to eliminate the threat of the Huáscar, which was the sole impediment to an invasion of the Peruvian coastline.

On the night of October 7 he was informed that the Huáscar had been seen near the port of Huasco and was moving north.
A trap was then set.
The Chilean fleet was divided into two groups.
The first division was in charge of Commander Galvarino Riveros and made up of the Blanco Encalada, Covadonga and the collier Matías Cousiño.
The first division would try to push Admiral Grau toward the second division that would be waiting further north.
In the early hours of October 8 the plan went into effect.
When the Huáscar and the Unión saw the Chilean ships blocking their way south they decided to turn back north.
 A few hours later they met the Cochrane which was waiting according to plan.
Admiral Grau was forced to fight in the Battle of Angamos while the Unión got away.

The Cochrane continued advancing on the Huáscar without answering its fire until it was very close to its adversary, in order not to lose speed.
When it finally attacked, the onslaught was ferocious.
The second shot destroyed the command tower of the Huascar, killing Admiral Grau and leaving the monitor without a rudder.
The fight continued for another hour, but the arrival of the Blanco Encalada with the rest of the Chilean fleet made any resistance totally hopeless.
The Huáscar was captured and became a part of the Chilean fleet.
On September 6, 1879 Latorre was promoted to commander of the ironclad Cochrane, the strongest unit of the Chilean fleet. His fame was such that he brought his entire crew with him. His first mission was to eliminate the threat of the Huáscar, which was the sole impediment to an invasion of the Peruvian coastline. 
On the night of October 7 he was informed that the Huáscar had been seen near the port of Huasco and was moving north. A trap was then set. The Chilean fleet was divided into two groups. The first division was in charge of Commander Galvarino Riveros and made up of the Blanco Encalada, Covadonga and the collier Matías Cousiño. The first division would try to push Admiral Grau toward the second division that would be waiting further north. In the early hours of October 8 the plan went into effect. When the Huáscar and the Unión saw the Chilean ships blocking their way south they decided to turn back north.  A few hours later they met the Cochrane which was waiting according to plan. Admiral Grau was forced to fight in the Battle of Angamos while the Unión got away.
The Cochrane continued advancing on the Huáscar without answering its fire until it was very close to its adversary, in order not to lose speed. When it finally attacked, the onslaught was ferocious. The second shot destroyed the command tower of the Huascar, killing Admiral Grau and leaving the monitor without a rudder. The fight continued for another hour, but the arrival of the Blanco Encalada with the rest of the Chilean fleet made any resistance totally hopeless. The Huáscar was captured and became a part of the Chilean fleet.
Juan José Latorre