[3][4] After laborious negotiations, the two ships were returned to the Spanish Navy at Gibraltar on 26 September 1873 and incorporated into Contralmirante (Counter Admiral) Miguel Lobo y Malagamba's central government squadron.

Thanks to a lack of naval officers in the Cantonalist fleet, a cavalry general, Juan Contreras y Román, took command of the Canton's squadron.

[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.

[5] The Cantonal squadron initially adopted a rhomboidal formation, with Numancia in the lead as Contreras′s flagship, her port and starboard sides covered by Méndez Núñez and Tetuán, respectively, and Despertador del Cantón bringing up the rear.

[6] They sighted Lobo's squadron, which was about 6 nautical miles (11 km; 6.9 mi) to the south in waters east of Cape Negreti and in no particular order.

[6] Numancia cut through the central government squadron's line between Diana and Almansa, then turned to starboard and crossed Carmen′s and Navas de Tolosa′s sterns as they fired at her, nearly all of their shots falling short.

[6] Ciudad de Cádiz passed south of the rest of the centralist squadron, fortunate to have avoided destruction and escaping with only a single hit to her paddle wheel.

Méndez Núñez opened fire on Vitoria and Almansa at very long range at 12:19, and most of the shots did not cover even half the distance to her targets.

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

[6] Méndez Núñez passed to the north of Vitoria around 14:00 and reached safety in Cartagena's harbor under cover of the guns of the coastal forts.

[5][6] With shots from both sides passing through her topsails, Thétis maneuvered to extricate herself from her predicament while Tetuán took advantage of the situation to steam to the west of Vitoria, closer to the guns of Cartagena's coastal forts.

[6] Vitoria scored hits that passed right through Tetuán and then, although the central government claimed she sustained no damage, broke off the engagement, steamed out to sea, and went dead in the water for at least an hour.

[5] Despertador del Cantón remained 5 nautical miles (9.3 km; 5.8 mi) south by west of Cape Agua and Cartagena's harbor all through the battle and did not engage the central government squadron.