The grenadiers who formed the leading party did not hesitate for a moment, but leaped into the unfinished ditch, clambered up the outer rampart, and with pike and bayonet attacked the defenders.
The captain's detachment speedily joined them.

The defenders gave way, broke, and fled, and in wild confusion both parties rushed into the bastion.

Peterborough and the prince with their two hundred men followed them quickly and in perfect order, and were soon masters of the bastion.
The earl at once set his men to work to throw up a breastwork to cover them from the guns of the inner works; and as there was plenty of materials collected just at this spot for the carrying out of some extensive repairs, they were able to put themselves under cover before the enemy opened fire upon them.
The attention of the garrison was wholly occupied by this sudden and unexpected attack, and the Prince della Torrella, a Neapolitan officer in temporary command of the fort, ordered all his force to oppose the assailants.

This was what Peterborough had expected.

He at once sent orders to Colonel Southwell to commence his attack upon the now almost undefended west bastion.