[2] Navas de Tolosa was commissioned in haste to reinforce the Spanish Navy during the ongoing Chincha Islands War[2] in the southeastern Pacific Ocean in which Spain faced the forces of Bolivia, Chile, Ecuador, and Peru.

She was ordered to proceed to Cádiz, Spain, form a division with the screw frigates Gerona and Princesa de Asturias, and make ready for wartime operations.

[2] She was assigned to the naval base at Havana in the Captaincy General of Cuba, from which she departed on 29 July 1866 bound for Rio de Janeiro, Brazil, where she joined the squadron of Contralmirante (Counter Admiral) Casto Méndez Núñez.

[2] On 24 December 1866, the Ministry of the Navy ordered Méndez Núñez to move to Havana and prepare to defend the Antilles against attack.

[3] Navas de Tolosa captured the Peruvian Navy steamer Rayo off Cartagena, Colombia, on 25 April 1867.

On 22 July she became the first Spanish Navy ship to fire at rebel forces, subsequently helping to put down the Cantonalist uprising in Cádiz by early August 1873.

[4] News of the passage of this squadron through Almería reached Cartagena on 9 October, and the Cantonalist forces there made plans to attack it.

[6] Later, during the night of 10–11 October, he ordered his ships to raise sail, probably to economize on their use of coal, and a strong north wind blew his squadron offshore and eastward to a position east of Portmán, Spain.

[5][6] At 11:30, the two squadrons sighted one another, with the Cantonal ships 3 nautical miles (5.6 km; 3.5 mi) due south of Cape Agua and Lobo's squadron about 6 nautical miles (11 km; 6.9 mi) to the south in waters east of Cape Negreti,[6] and the Battle of Portmán began.

[6] After exchanging fire with Vitoria, Numancia cut the central government line between Diana and Almansa, and crossed astern of Navas de Tolosa and Carmen.

[6] Vitoria broke off to chase Numancia, leaving Navas de Tolosa, Almansa, and Carmen to face the approaching Méndez Núñez and Tetuán.

[6] Navas de Tolosa, Almansa, and Carmen were steering toward Cartagena in the wake of Numancia and Vitoria,[6] putting them on a converging course with Méndez Núñez.

They exchanged fire with Méndez Núñez at very long range, but most of the shots were wild and neither side suffered damage.

[6] Passing Almansa, Carmen, and Navas de Tolosa, Tetuán steamed toward Diana, but upon discovering that the other Cantonal ships had fled, she turned around off Cape Negreti and slowly steamed back towards Cartagena, again engaging in succession Carmen, Almansa, and Navas de Tolosa.

[2] As 1875 wore on, Navas de Tolosa operated in the Cantabrian Sea along the northern coast of Spain, taking part for a short period of time in the Third Carlist War.

[2] After a ceremony for the exhumation of the remains on 27 November 1882, they were taken from San Lorenzo Island off Callao to the cemetery in Lima, Peru, where a mausoleum had been built for them.

[2] Navas de Tolosa arrived at Cádiz in such poor condition that the Spanish Navy decided to decommission her and issued orders on 22 September 1884 for her to be scrapped.

[2] In 1885 the Estado General de la Armada ("General State of the Navy") listed Navas de Tolosa as disarmed, but amid a crisis in which Spain feared a war with the German Empire over the status of the Caroline Islands in the Spanish East Indies, the Spanish Navy considered refitting her for service in September 1885.