The French squadron closed with the harbour during the morning, "Victor" entering the channel under Île de la Passe at 1:40 pm. As "Victor" passed "Nereide" and the fort Willoughby opened fire, Lieutenant Nicolas Morice surrendering the outnumbered corvette after the first volley. Willoughby sent boats to attempt to take possession of "Victor", but they were unable to reach the vessel. Behind the corvette, "Minerve" and "Ceylon" pushed into the channel and signalled Morice to follow them, exchanging fire with the fort. As Morice raised his colours again and followed "Minerve", a large explosion blasted out of Île de la Passe, where the false French flag had ignited on a brazier as it was lowered and set fire to a nearby stack of cartridges, which exploded in the close confines of the fort. Three men were killed and 12 badly burned, six cannon were dismounted and one discharged unexpectedly, killing a British sailor in a boat attempting to board "Victor". With the fort out of action and a significant number of her crew scattered in small boats in the channel, "Nereide" alone was unable to block French entry to Grand Port. With Willoughby's ambush plan ruined, the scattered boats sought to rejoin "Nereide", passing directly through the French squadron. Although several boats were in danger of being run down by the French ships and one even bumped alongside "Minerve", all eventually rejoined "Nereide" safely. The opportunity to cause significant damage to the French in the narrow channel had been lost, with "Bellone" joining the squadron in passing through the channel with minimal resistance. In addition to British losses in the explosion at the fort, two men had been killed and one wounded on "Nereide". French losses were more severe, "Minerve" suffered 23 casualties and "Ceylon" eight. With both sides recognising that further action was inevitable, Willoughby sent a boat to "Sirius" requesting additional assistance and Duperré sent a message overland with Lieutenant Morice, requesting support from Hamelin's squadron (Morice fell from his horse during the mission and was severely injured). Command of "Victor" passed to Henri Moisson. In the afternoon, Willoughby used mortars on Île de la Passe to shell the French squadron, forcing Duperré to retreat into the shallow harbour at Grand Port and Willoughby subsequently sent officers into Grand Port on 21 August under a flag of truce, demanding the release of "Victor", which he insisted had surrendered and should thus be handed over to the blockade squadron as a prize.