As Porter closed with the enemy convoy, he disguised his ship as a merchant vessel by ordering all gunports closed, the sails reconfigured more haphazardly, and most of his crew hidden from sight. The ruse worked, and the Essex was able to approach the convoy without raising suspicion. That night, using the cloak of midwatch darkness to his advantage, Porter brazenly inserted the Essex into the enemy convoy and managed to cut out and capture the last ship in the group. She was the Samuel and Sarah and was carrying about 200 soldiers and $14,000 in cash.
In the weeks to come, Porter would capture seven more merchant ships. It was already a successful cruise by nearly any measure, but the best was yet to come.
On 13 August, off the coast of Newfoundland, a lookout in the Essex's maintop spotted a Royal Navy sloop that proved to be HMS Alert. To lure the British warship in to striking range, Porter again disguised his small frigate as a merchant. Taking the bait, the Alert closed to within two miles before her captain realized his mistake. At this point, unable to flee from the speedy Essex, the Alert continued to close and opened fire. Her shots did little damage, but when the Essex replied with a full broadside it was a different story indeed. It was a withering blast, quickly followed by several more. The battle was over in less than ten minutes when the Alert struck her colors.
Not only did this action give Porter the honor of scoring the first capture of a British warship in the War of 1812, but this first cruise was to have an important effect on the conduct of the remainder of the war as well. In roughly the same period that Porter had scored these multiple successes, Rodgers' squadron had managed to capture a mere seven merchants, despite having taken his three large frigates, a sloop, and a brig across the Atlantic and back. When compared to Porter's success as a lone wolf, this poor showing convinced Hamilton to shift to the strategy originally proposed by Decatur. Before long, Decatur and others would defeat their British counterparts in one-on-one sea fights that would not only astound the world but inject a much needed boost to national morale in some of the darker days of the war.