With the battle still raging and the fighting very intense when, as we said, the King of Castile fled, it began to become clear that the battle was being completely won, with the enemy banner brought down and large numbers of the Castilians being killed, as well as most of the renegade Portuguese who constituted the front ranks of the vanguard.

With the king and the constable pressing forward in pursuit of a victory that was now obvious to all, the king told the constable that the foot soldiers in the rearguard were in great danger from the large numbers of Castilians who were harassing them and that he should go to their aid. This was in fact true, because Gonzalo Núñez, the Master of Alcántara, accompanied by a group of light horsemen, was riding into the Portuguese rear and was vigorously attacking the foot soldiers and crossbowmen posted there to protect the baggage train. They were defending themselves with arrows and darts in such a way that those on horseback could not inflict any damage on them but were actually damaged by them, with numbers of them dying from crossbow shots or lance thrusts. This attack benefited the Portuguese, because the foot soldiers in that sector, though they wanted to flee, were unable to do so, and thus they were forced to defend themselves. Afterwards, the Castilians realised that this had been an unwise tactic, because they had not left their enemies an open escape route.

At once the constable, fighting on foot as he was and acting on the king's orders, turned towards the rearguard, but owing to the great travail that he had undergone, he was unable to make as much headway as he wanted, nor had he a mount to ride. However, Pedro Botelho, grand commander of the Order of Christ, who was riding a fine horse, spotted that the constable was on foot, and so he dismounted and presented it to him. The count thanked him most warmly, mounted up and galloped to the aid of the foot soldiers fighting in the rearguard. He found them in great peril, as they were being hard pressed by large numbers of Castilians, to such a degree that they were anxious to scatter when he arrived.