After the battle of Concon the opposition forces advanced upon Valparaiso, and two days later endeavored to capture Fort Callao, at Viña del Mar, a beautiful suburban place six miles from Valparaiso. The fortress, which commands the bay of Valparaiso, the valley and surrounding heights, being equipped with modern guns, and well-nigh impregnable, resisted the attack of both warships and artillery, and a repulse prevented a direct advance upon Valparaiso, the objective point of the Congressional army. Retiring from Viña del Mar, Generals Canto and Korner, commanding the revolutionary forces, fell back to Salto, a few miles distant, where they destroyed a railway bridge spanning the river, thus cutting off communication with Santiago, and preventing the possibility of Balmaceda forwarding troops from the capital. Making a detour of some thirty miles, the revolutionists endeavored to approach Valparaiso from the south, but encountered the government forces, under command of Generals Barbosa and Alzerreca, occupying a formidable position upon the hills near Placilla, a few miles from the city of Valparaiso. This was on August 27th. On the 30th the election of Señor Claudio Vicuña would be formally ratified by the Senate, and he would become president. It was important to the revolutionists to force a decisive engagement and overthrow Balmaceda before the newly elected president should take his seat. Before daylight on the morning of the 28th, under cover of the darkness and protection of the hills, the revolutionists got into position to give battle without being seen by the government forces. Early in the morning as the advancing army was crossing an open plain Balmaceda’s troops opened an artillery fire upon it, and the battle of Placilla, the final and decisive engagement in the revolution, was begun. The opposition forces numbered about twelve thousand and the government, nine thousand. The former, flushed with success and inspired with the hope of final victory, fought like demons, while the latter, discouraged and disheartened with failure, menaced with disaster and annihilation, showed lack of order, discipline, and courage manifested and displayed on previous occasions. Some companies even deserted and joined the enemy during the battle. After a few hours’ terrific fighting, in which more than a thousand men were killed and a greater number wounded, on the government side, the Balmaceda army was put to rout. The victorious forces which had lost five hundred killed and over a thousand wounded, pursued the fleeing remnants of the routed army, driving many of them into the quebrades (ravines), where they were unmercifully slaughtered. Generals Barbosa and Alzerreca were both killed in the engagement. On the evening of the 28th, Valparaiso was in possession of the revolutionists and the Balmaceda government was overthrown.