Great Britain's Hector Pardoe came sixth in the men's open water swimming marathon in the River Seine, which was won by Kristof Rasovszky of Hungary.
Rasovszky, who was second in Tokyo three years ago, won in a time of one hour 50 minutes 52 seconds, just 2.1 seconds ahead of Germany's Oliver Klemet while Hungary's David Betlehem took bronze.
Tobias Robinson was 14th for GB while Team Ireland's Daniel Wiffen, who won 800m freestyle gold and 1500m bronze in the pool, was 18th as he made his open water swimming debut.
It was a strong effort by Pardoe, who won bronze in the World Championships last year, after he was forced out of the Tokyo Games on the final lap when his goggles split.
Pardoe was caught in a crowd of swimmers over the first lap and crossed the line in 14th place, but managed to work his way into the top 10 midway through the second turn.
However, he could not do anything to challenge Rasovszky, who led from the off, with the iconic backdrop of the Eiffel Tower and Grand Palais.
Florian Wellbrock of Germany, who took gold in Tokyo, challenged the Hungarian at the front of the field but dropped away with a lap remaining.
It was Klemet who emerged as the nearest challenger over the final lap but Rasovszky held on in a sprint finish to take gold, while Betlehem made it two Hungarians on the podium.
Almost a minute down on the leaders, Pardoe claimed sixth in a photo finish with home favourite Marc-Antoine Olivier.
Wiffen, who had done no extra training for the open water as he focused on his pool events, came home a commendable 18th as he completed the 10km within two hours.
It caps a remarkable Olympics for Wiffen, who became the first athlete from Northern Ireland to win a gold medal in 36 years in the 800m freestyle at the start of the Games before he claimed bronze in the 1500m.
It is the last race of the Paris Olympics to take place in the Seine, which had been a major talking point before and during the Games over the water quality of the river.