At midnight, they landed at Estero Longa Lemo, and continued on foot, until they reached the first sentry outpost at the entrance to the town. They had, as a guide, and Englishman who had been a prisoner in Porto Bello, and was familiar the layout of the town. With 4 others, he proceeded to the guardhouse, and captured the sentry. The sentry was taken back to Morgan, who tortured him to reveal the troop strength, their locations, etc.

They continued on to the town, and about 15 minuets later, reached a small fort at the entrance to the town, which they surrounded. Morgan shouted to the defenders to surrender, and he would spare their lives; but, they decided to fight, and put up a stiff defense. The shooting warned the town, and the large fortresses that something was wrong. When the pirates took the fort, they proceeded to blow it up, with all the defenders and the captured sentry inside.

Once this was done, the pirates rushed the town, catching many of the citizens, still in bed. Those that had heard the commotion, proceeded to hide their treasures, and run from town. Some escaped into the jungles, while others sought refuge in the Fort of Santiago and San Jeronimo. The pirates split into several groups, as previously planned. A couple of groups attacked the three fortresses guarding the harbor. Another group proceeded to all the churches and cloisters, and captured all of the priest, monks  and nuns in the town. Another group went after the Royal Treasure House, and different warehouses in town.

The governor had retreated into San Jeronimo, and was directing the defenses from there. The Spaniards were able to resist all of the attacks by the pirates. Morgan stationed his sharpshooters, where they could pick off the Spaniards, as they reloaded their cannons, and were able to kill over 8 of them. Morgan kept offering safe passage, for the garrison in the forts, but the governor responded with "Más vale morir como soldado honrado que ser ahorcado como un cobarde" (Better die as an honorable soldier than hung as a coward). The pirates would assault the walls of the forts with huge ladders, hoping to scale the walls; but were beaten back. The defenders would push off the ladders, hurl huge stones, over 50 pots full of gun power, and shoot back. By noon, things were at a stalemate, and the pirates had lost a lot of men. The buccaneers had to capture the forts, since the town richest and most important citizens, has sought refuge there, taking with them all of their treasures.

Early in the afternoon, the pirates that were attacking the fort of Santiago, took the fort, and raised the English flag over the fort. The renewed the quest to capture San Jeronimo, and they attacked with more vigor. San Jeronimo was an important symbol for the pirates, since what they were after, booty, was mostly hidden there. Morgan then came upon an idea, and sent for all of the religious to be assembled on the battle field. He informed the governor, that monks and nuns, were going to be carrying the ladders, leading the assault. 

He then order the monks and nuns, to carry the large scaling ladders, and had to shoot a couple, before the rest did as instructed. As they approached the walls, the defenders, ordered by the governor, started firing on them. They pleaded with the governor, to surrender, and spare them, but he refused. The pirates advance, using the priest and nuns as shields. Once the ladders were against the walls, the pirates swarmed on them, but were again, beaten back by the defenders. Many of the priest and nuns were either killed or wounded during this assault.

Some of the pirates, were eventually able to set the main doors at the main gate on fire. As soon as they burned down, the pirates charged through the gate and encountered heavy fire from the defenders. The pirates were using a lot of hand grenades and stink-pots. Eventually, they got the upper hand, and slowly started taking over parts of the fort. The governor refused to surrender, and was eventfully shot by the pirates. The governors wife and daughter, pleaded with him, to lay down his sword, and spare his life, but he refused.

As soon as San Jeronimo was captured that evening, all of the men were rounded up, and locked up in a secure building. The women were locked in the cathedral and the wounded Spaniards were taken to a warehouse, to die. All of the wounded pirates were taken to a large building, to be treated by their surgeons. After they secured the town, the pirates attacked the wine, and some of women, (the rich were spared, since they could be ransomed). 

The next day, the pirates began to search for all of the gold, silver and jewels they would find. All of the town people were taken individually, and interrogated for the whereabouts of their treasure. Those that quickly revealed its location, were spared. Those that resisted were tortured until they talked, and  if they failed to reveal its location they were executed. If they talked, before they died, their life was spared if they did not resist, until they were almost dead. Many of the poor, were tortured and killed, although they pleaded that they had none to hide and did not know where some was hidden.  Other prisoners were made to point out the rich people in town. The nuns and priest that survived the assault on the fort, were all tortured and killed.

Meanwhile, the governor of Panamá, received work of the happenings at Porto Bello. He set out to raise a large force, to go and free the town from the clutches of the pirates. Morgan, suspicious of a counter attack from Panamá, sent a force of 100 men, to prevent such an attack. The force walked down the Camino Real, until they found a place that they could ambush any force that came from Panamá. When the Spaniards approached, the pirates opened fire, and caused such a commotion, and killed so many of the Spaniards, that they retreated, in a mass disorganized mob, returning to Panamá.

The governor of Panamá was so impressed, that a small band of men were able to defeat an army, sent Morgan a message, inquiring about the nature of the weapons the used, and could he please send him a sample of this wondrous weapon. He also informed Morgan that if they did not abandon Porto Bello, a larger force would be sent to capture all of the pirates. The governor, realized that he was no match for the buccaneers, and decided to forget about Porto Bello, and leave them to their own resources.

Morgan sent the governor, a French musket with a 4½ feet barrel, firing a one once ball. He also sent a bullet belt, with 20 cartridges of power. Morgan also told him, not to worry about returning it, since Morgan would be back in a year or two, to personally pick it up, at Panamá. The governor sent Morgan a gold ring, with a rosette of emeralds. He also told Morgan, that he tried to come to Panamá the way he went to Porto Bello, his reception would be very different. 

A short time after the fall of San Jeronimo, San Felipe surrendered, and the pirates controlled the entire harbor of Porto Bello. The ships were sent for, and were loaded with all of the treasures taken. They also took on food and water, for the trip home.

Most of the pirates that were wounded during the battle, died from their injuries. All of the Spaniards that were wounded, died, since the pirates did not allow them to get medical care, and refused to feed them. The town folks, had to scavenge for food, since the pirates took all they found for themselves. They fed the prisoners scrapes, and some of them died of hunger. 

Morgan spent 2 weeks in Porto Bello, making sure that they found all of the treasures available. He also informed the leading citizens of the town, that if they did not pay a ransom, for the town, it would be burnt to the ground, and all of the fortress blown up. The citizens were able to find some money, for their ransom, but it was no where near, what Morgan had demanded. Even so, Morgan spared the town from further damage.

Before he left, Morgan took the best brass cannons he could find, and proceeded to spiked the rest of the cannons. The pirates made off with 215,000 pieces of eight in currency, gold, silver ingots, and jewels. They also captured a large quantity of linen, silk and spices.