[1] A patriotic force, under the control of Manuel Blanco Encalada, a Chilean naval officer and later vice-admiral, had advanced towards the town of Talca, which was being held by the guerrilla leader Ángel Calvo.

Calvo was a Chilean landowner, a former patriot who had switched sides to the Royalists during the Siege of Chillan the previous year.

Manuel Blanco Encalada arrived in Quechereguas, where he received a note from Ángel Calvo proposing a site for the forthcoming battle.

The patriot forces collapsed, and a large number of officials and several unit commanders fled back towards Santiago.

In a quarter of an hour, 450 Royalists had defeated 1,400 patriotic soldiers, taking 300 prisoners, food, ammunition, and guns.