Australia's Jessica Fox still has a chance of making it three gold medals out of three in canoe slalom after she successfully negotiated a chaotic first-round kayak cross race on Saturday to qualify directly for Sunday's heats at the Paris Olympics.

Second in Friday's time trial, in which racers surged down the course one by one, Fox ended up second again in her Saturday race as the enthusiastic crowd at the Vaires-sur-Marne whitewater venue got their first taste of the frenetic nature of head-to-head kayak racing.

American Evy Leibfarth, fresh off Team USA's first medal in canoe slalom since 2004, finished sixth in the time trials and won her race to avoid the repechage and automatically qualify for the next phase. 

Riding in crafts that weigh about twice as much as their regular slalom kayaks, the racers were grouped in threes and fours and it did not take long before the boats were banging and paddles flailing as they sought to be fastest to the bottom of the 210-metre course.

Saturday's first round and repechage whittled down the fields from 38 men and 37 women to the 32 who will face off in Sunday's heats, with the quarterfinals, semifinals and finals all on Monday.

In the second heat Fox, who has collected both gold medals in canoe and kayak slalom so far, had to be content with second place in her heat after being out-sprinted by Germany's Elena Lilik.

WOMEN'S RESULTS

Fox's sister, Noemie Fox, won the first of the day to feature four competitors, creating the intriguing prospect of the two Foxes facing each other later in the competition.

"We've practised together, we've raced together before and we are really good at reading each other, and top two make it through each round," older sibling Jessica said.

"As much as we can, we are going to be working together to make sure we are the top two but if it comes down to it, (she will) absolutely go for me, and vice versa."

World No. 1 Joe Clarke blazed to victory in the first men's heat, and he relished the combative nature of the racing.

MEN'S RESULTS

"I think what I love the most is that it's never over until it's over — you'll see people go from first to fourth, from fourth to first, faults and mistakes coming in, and you've just got to keep going," he told Reuters.

He was proved right minutes later when refugee athlete Amir Rezanejad capsized and came out of his boat before Lukas Rohan of the Czech Republic bullied his way past Andy Barat in the next race and into Sunday's heats, leaving the paddler from Comoros to head for the repechage.