In February 1758 he was with the squadron under Admiral Osborn, shutting up M. de la Clue in Cartagena, when on the 28th the Marquis Duquesne, with three ships, attempted to raise the blockade.
The Foudroyant, carrying Duquesne's broad pennant, was the ship in which M. de Oalsonnière had hoisted his flag in the battle of Minorca, and, notwithstanding her enormous size, Gardiner had been heard to say that if he fell in with her, in the Monmouth, he would take her or perish in the attempt.
It is, perhaps, more probable that the story was invented afterwards; for it was by the mere accident of position that the Foudroyant was chased by the Monmouth, the Swiftsure and Hampton Court, each of 70 guns, following.
The fight was gallantly continued by the first lieutenant, Robert Carkett, and on the Swiftsure coming up about one o'clock, the Foudroyant hauled down her colours.
The great disproportion between the combatants, the Foudroyant being an unusually large and heavily armed ship of 8O guns, and the fact that the Monmouth alone had beaten her gigantic adversary almost to a standstill before the Swift sure came up, as well as the circumstances of Gardiner's death, have all combined to render the action one of the most celebrated in the Royal Navy's annals; and that this distinction should have been achieved by a pupil of Byng and Griffin is perhaps not its least remarkable feature.