The Confederate steamers came out of the harbor early on the morning of the 21st. The wind was very light, so the steamers were able to quickly gain ground on the Union vessels. When the steamers came within range they opened fire, and the Union vessels answered with broadsides. The conflict continued this way for two hours, until the Confederate ships were able to draw up close enough that the infantry on the decks could open fire. Assistant Surgeon J. W. Sherfy of the Morning Light wrote:
It was impossible for the men to remain at the guns under the galling fire from the enemy's sharpshooters. They had come within close range upon our port and starboard quarters, and from their elevated position completely swept our decks. An effort was now made to train the two aft guns upon the enemy and fire through the cabin, but as it was impossible to get such a bearing as would offer a reasonable chance of inflicting any damage, and the men were now all driven from the other guns, the commander, deeming further resistance useless, reluctantly determined to surrender, and our flag was hauled down.Both ships were captured, with a handful of men having fallen on both sides. Although this action temporarily cleared the blockade off of Galveston, it did not last long, as the Union navy soon sent stronger ships to take up the blockade.