Before this desperate situation, Monteverde tried to reconquer Maturín, as the provinces of Guayana, Nueva Barcelona and Cumaná had fallen to Mariño quickly, but he failed on multiple occasions.

When he tried to stop Bolivar in the West, he was wounded in battle and was forced to take refuge in Puerto Cabello, where Cajigal relieved him from command.

[10] On 23 March, the Patriot army in the West and its partner in the East, under the command of Bolívar and Mariño respectively, met in Los Pilones - currently Guárico State - in order to join forces against the Royalists.

[18] The war began at 3:00 PM, when the division of Rafael Urdaneta opened fire on the enemy who were trying to outflank the Royalists to the right, but this was a trick to distract Cajigal.

The main attack occurred straight in the center with José Francisco Bermúdez, Juan Manuel Valdes and Florencio Palacios advancing.

In response to this, Bolívar ordered to Santiago Herrera to let the cavalry of José Gregorio Monagas, John Josephus Rondon and Lucas Carvajal attack the Carabineros de Granada, while Diego Jalon's Patriot artillery dedicate themselves to bombard the Royalist Staff position, forcing them to relocate several times without the possibility to react.

After being attacked by the Patriot Lancers' cavalry, the Carabineros de Granada started to retreat, dragging along with them the Royalist infantry, which broke ranks and fled in panic.

Cajigal escaped to Apure[15] and granted broad powers to Boves to continue this campaign, but he retired to Los Llanos to take care of his elderly grandmother who was sick with tuberculosis.

Meanwhile, José Tomás Boves left with a powerful Royalist army from Calabozo in a campaign that ended in the Second battle of La Puerta.