Vaasco ordered his mercenary spearmen recruited from the countryside to take up the ram and push it to the game while the rest of his infantry followed. His plan was to simply overwhelm the outnumbered, tired, and hungry rebels with the sheer weight of his infantry. His forces outnumbered the rebels by almost 150 men, but it was not just the numbers advantage that gave Vaasco confidence. His men were well trained, armed, and armored, while El Cid had obviously left the cheapest garrison possible, assuming the Spanish would attack first at Valencia instead of Zaragoza. These were peasants who were given the least amount of training possible and armed with a crudely made spear or a hunting bow. They would be no match for his forces, and their wooden gate would be no match ram. It broke through in a matter of minutes.
The Spanish infantry charged through the broken gates into the city, where the rebels had organized a defensive line on a small hill just behind the gate. The lines smashed together viciously, and the weight of the Spanish forces almost immediately began to push the rebel line backward towards the town square. After several minutes of fierce fighting, the rebel militia broke and began fleeing back to the square for one last stand against "oppression."
Meanwhile, General Vaasco had led his small force of heavy cavalry had slipped into the city via a side gate, and now they attacked the town square, where the rebels had left a small force of about 60 crossbowmen to defend it. Vaasco only had 20 cavalrymen with him, but they quickly slaughtered the crossbowmen and took possession of the town square. When the fleeing rebels reached the square, they found not their companions ready to fight, but more Spanish ready to cut them to pieces. Every rebel was massacred, and Zaragoza was won for Spain.