At 6a.m. on 27 July, with the British fleet roughly line-abreast, Keppel gave the order for the rear division, several miles away under Sir
Hugh Palliser, to chase to windward. At 9a.m., the French, who had hitherto been sailing in the same direction, several miles to windward, went about once more. As the rearmost ships of the French fleet were tacking, however, the wind changed allowing the British to close the gap between them and their quarry. At 10:15 the British were slightly to leeward, line-ahead on the same course as the French. A little later, a change in wind direction brought about a rain squall which cleared at around 11 o'clock. A further change in wind direction to the south-west gave advantage to the British which d'Orvilliers sought to negate by ordering his ships about. The French, now heading towards the British in a loose formation, would pass slightly to windward. The French ships were a few points off the wind and d'Orvilliers ordered them close hauled which caused the French line to veer slightly away from the British. The battle began at 11:20 when the fourth French ship in the line was able to bring her guns to bear. Keppel, who wished to save his salvo for the enemy flagship, received the broadsides of six French ships without reply. Once he had engaged the 110-gun , he continued to attack the next six ships in the French line. As the British van under
Robert Harland passed the end of the French line, Harland ordered his ships about so as to chase the French rearguard, including the . Palliser's ten ships at the rear had not formed line of battle but were instead in a loose irregular formation. This was in part due to Keppel's earlier order to break off and chase the French ships to windward. Palliser's division therefore was badly mauled, having allowed itself to be attacked piecemeal. At 1p.m.
Victory passed the last French ship and attempted to follow Harland but was so badly damaged in the masts and rigging that Keppel had to
wear round and it was 2p.m. before his ships were on the opposite tack. It was about this time that Palliser in
Formidable emerged from the battle, downwind of Keppel's division. Meanwhile, the French line had tacked and was now heading south on the starboard tack and threatening to pass the British fleet to leeward. The French practice of firing high into the rigging had left several of the British ships disabled and it was this group that Keppel now stood down towards whilst making the signal, 'form line of battle'. By 4p.m., Harland's division had gone about and joined Keppel's ships in line but Palliser would not or could not conform and his ships, misunderstanding Keppel's intentions, formed line with their commander, several miles upwind from the rest of the British fleet. D'Orvilliers did not, however, attack the British fleet while it was divided into three sections but instead continued his course, passing the British fleet to leeward. At 5p.m., Keppel sent the sixth-rate, , to demand that Palliser join the main body of the fleet and when this failed, at 7, Keppel removed Palliser from the chain of command by individually signalling each ship in Palliser's division. By the time those ships had joined Keppel, night had fallen and, under cover of darkness, the French fleet sailed off. By daylight the French were 20 miles away and with no chance of catching them, Keppel decided to return to
Plymouth to repair his ships. ==Aftermath==