Connecting with them with a battery of substantial guns, a few US Infantry charges were driven back once more. Nonetheless, the freshness of the supporting Mexican brigades, a large portion of whom were untested volunteer army units, saw the bridgehead traded off. At the point when additional ammo arrived, the nine and a half drachm cartridges ended up being just good with the Saint Patrick's Brown Bess guns of which there were few in contrast with the Mexican rifles.

A stray start from a big guns piece discharging grape shot at the charging Yankees set land a part of the recently arrived ammo, and in the subsequent blast, Captain Santiago O'Leary and General Anaya were severely copied, as the Saint Patrick's were compelled to withdraw behind the religious circle dividers.