On Saturday, April 17, 1830, a three-hour battle was fought near the confluence of the Claro and Lircay rivers, just outside the town of Talca in the Central Valley of Chile. The smaller of the two armies was led by General Ramón Freire, the liberal-minded hero of the wars of independence who had been Chile's president a few years earlier. His adversary, General Joaquín Prieto, another veteran of independence, was the champion of the Conservatives who had recently seized power in Santiago, the capital, bringing to an end the series of false starts that had marked Chilean politics since 1823, mostly under the leadership of politicians calling themselves Liberals. With reinforcements brought by Colonel José María de la Cruz from Chillán, Prieto had assembled a force of around twenty-two hundred. It quickly overwhelmed Freire's seventeen hundred soldiers, many of whom fled for their lives across the little Lircay river, leaving behind them around two hundred dead.

General Prieto's victory at the Battle of Lircay (as it became known) assured the triumph of the new Conservative regime. Eleven days earlier, the Valparaiso trader Diego Portales had taken over two of the three portfolios in the Chilean cabinet, thus becoming the most powerful figure in the country. At Portales's behest, General Prieto would soon be elected president of the republic. His victory at Lircay and Portales's rise to power ushered in more than a quarter century of Conservative rule in Chile.