After becoming fully operational and ready for duty the General Concha was assigned to the then Spanish colony of San Juan, Puerto Rico where she served mainly as a coastal surveillance vessel until the Spanish–American War began in April 1898.

On 22 June 1898 General Concha, the cruiser Isabel II, and the destroyer Terror came out of port to test the blockade, resulting in the Second Battle of San Juan.

On 28 June 1898, General Concha, Isabel II and gunboat Ponce de León left port again to assist a Spanish blockade runner, the merchant steamer Antonio López, trying to make its way into San Juan's harbor with an important cargo of war supplies.

She was assigned to the Mediterranean coast of Morocco, as part of the effort to interrupt piracy and arms smuggling by the local cabilas, usually patrolling the area between Melilla and Alhucemas.

The armed boat nr.2 was launched, with eight seamen led by Alférez de Navío Don Luis Felipe Lazaga with the mission of reaching Alhucemas to communicate the distress of the vessel and also evacuate Colonel Basterra.

The local insurgent forces soon realized the compromised situation of the Spanish vessel and began harassing the crew of General Concha with spare rifle shots from the nearby cliffs.

With a rope he wrapped around himself a mattress as improvised protection and came to the outside deck, exposed to fire, dragging all the wounded and dead to the inside of the ship for treatment.

About 12:30 the attackers left their positions and began an assault on the wrecked ship, boarding her by the partially submerged bow section and taking several prisoners here.

But in the aft section the Alférez de Navío Ramos had rallied all remaining and able crew (some 20 or 25 men), most armed with rifles and some others with revolvers and even with axes launched a counterattack as a last chance to maintain control of the ship, forcing the looters in the bow to withdraw from the deck back to their row boats with many casualties.