French canoeists Nicolas Gestin and Camille Prigent gave the rain-soaked fans plenty to cheer about with some blistering slalom runs at the Olympics Vaires-sur-Marne Nautical Stadium on Saturday.

Gestin came out on top in the men's single slalom heats while Prigent led after the first run and ended up in third place in the women's kayak single heats to send the crowd home happy.

The women's standings were topped by French-born Australian athlete Jessica Fox, who powered through the very last run of the day in a time of 92.18 seconds.

Leading after the first run in the pouring rain, Gestin gained more than a second on his final time down the course to qualify for the semi-finals in first position with a time of 88.78 seconds, the only racer to break the 90-second mark on the day.

"I feel great, the atmosphere was insane. I was so happy to race here ... I put my boat on the start and had to say, 'Nico keep your focus', it was so loud," Gestin said

With the 16 fastest racers after both runs going through to the semi-final and the remaining four eliminated, Britain's Adam Burgess nabbed second spot thanks to a time of 90.87 from his first run, with Croatia's Matija Marinic third.

Ireland's Liam Jegou pulled out a tremendous second run of his own to grab the 16th and final spot, edging out Dutch competitor Joris Otten with a frenetic performance that saw him improve his time by almost 3 seconds to qualify.

The venue DJ blasted out high-energy music to keep the crowd's spirits up, but the whitewater action showcasing the speed, skill and raw strength of the athletes kept them engaged, despite the rain.

With 22 of the 25 competitors going through, there was little jeopardy in the women's competition, but that did not stop the athletes from throwing themselves at the course with abandon.

A flawless second run from American Evy Leibfarth saw her jump from eighth place into the lead but Klaudia Zwolinska of Poland overtook her with a time of 93.03 seconds before Prigent tore through the water on her final try.

The 26-year-old came close but got stuck on a couple of occasions on the latter part of the course, ultimately ending in third place after four-time Olympic medallist Fox made a brilliant descent through the course to win by 0.85 seconds.