A division of boats with sailors and marines of the First Chilean Navy Squadron, commanded by Thomas Cochrane, stealthily advanced towards Callao and captured the ship through a boarding attack.

British historians Brian Vale[4] and David J. Cubitt[5] follow the same line of opinion when affirming that Spain had unquestionably lost control of the sea against the Chilean Navy.

[7] The Viceroy Juaquin de la Pezuela entered into negotiations with San Martin, based on the new political situation in the Iberian Peninsula with the proclamation of the Spanish Constitution of 1812.

[9] At the beginning of October, San Martin sent a division of the army to the Peruvian highlands to win the territory over for the Patriots, giving the command of this force to General Juan Antonio Álvarez de Arenales.

[12] Since the arrival in September of the liberating expedition to the Peruvian coast, the Spanish Navy had not accomplished any effective actions to repel or at least harass the revolutionaries, granting them control of the sea.

[1] This was the situation of the Spanish fleet at the time when Cochrane had established the blockade of Callao on 30 October, having at his disposal the frigates O'Higgins and Lautaro, and the corvette Independencia.

[19] On the basis of his own information and that of a subordinate,[20] he decided to undertake a surprise assault, entering the port at night with several boats and seizing the Esmeralda by means of a boarding attack.

[39] On the afternoon of 5 November, Cochrane ordered Lautaro and Independencia to sea, leaving O'Higgins near the island of San Lorenzo, and on its hidden side, the boats with their crew destined to attack.

[41] At midnight, the boats arrived at the entrance to the floating chain barrier and saw a gunboat guarding the place, with a lieutenant and 14 men on board, so they approached and surprised her, managing to capture her with the crew and preventing an alert.

[Note 4] The sleepy crew, newly aware of the attack, took up arms to counter-attack, but as Cochrane later stated: "the Chilean machetes did not give them much time to organize and recover their spirit".

[45] During the fight, Cochrane received a blow at the beginning and in the final stage a shot that pierced his thigh, leading him to sit on the deck and try to direct the attack as best he could.

[45] The few sailors that the officers managed to embark[50] attacked Maipú and Pezuela, but were repelled by the by-now prepared ships, with the support of several gunboats directed by Vacaro, who was patrolling the bay.

[51] Finally, Cochrane ordered Guise to take Esmeralda out of the bay, beginning to move outward along with all the boats and two captured gunboats; the one that watched at the entrance of the floating chain and another that had approached the frigate during the climax of the fight.

Several shots hit the Esmeralda, one entered through one of the stern windows and damaged the quarterdeck, causing the death of some men and wounding Coig, who was being held prisoner there.

A little known fact referred by an eyewitness of the attacking forces affirms that one of the boats that belonged to O'Higgins had gone astray, and that during the rest of the night the batteries continued to open fire, without understanding the reason.

[55] The doubts disappeared when the sun appeared and the missing boat was seen leaving the port, towing a large gunboat that it had captured, quickly receiving assistance.

[55] Chilean naval researcher Jorge Ureta Muñoz affirms that the main factors that contributed to the successful capture of the frigate are due to the coordination of the details, the general idea of a proven plan, the efficient and energetic execution led by Cochrane himself, and the value of its participants.

[31] It also highlights the great importance that the realization of a naval action of this type can have, in the sense that with proportionately limited means, an extraordinary advantage can be obtained, also mentally, by dislocating material from the adversary, at a minimum cost.

[56] The Spanish historian Fernández Duro compares this naval action with the capture of the Hermione, in Puerto Cabello, in 1799, but affirming that he surpasses it in daring.

The Chilean historian Barros Arana indicated in his book written in 1894, that this naval action has been the battle of the Spanish American wars of independence that has been narrated most often in diverse historiographical works.