Fox, bidding for a third K1 crown, stopped the clock at 94.14sec to qualify for the semi-finals of the event at the Deodoro, the venue used when the Brazilian city hosted the 2016 Olympic Games.

The 24-year-old finished ahead of reigning Olympic champion Maialen Chourraut of France, who is returning to the scene of the greatest triumph of her career.

"It's obviously a different situation two years on but it's nice to be back and I have some good memories here," said Fox.

"Obviously with Rio, it was amazing to win a second Olympic medal. 

"But I was left a bit frustrated because I felt like it wasn't my best race.

"That's what I’ll be looking for next, just one run at a time. 

"The semi will be next, and then if I make the final, the goal will be to give it everything and have no regrets at the bottom."

In the men's C1, Slovakia's Michal Martikán was the fastest qualifier as the five-time Olympian, who did not compete at Rio 2016, finished in 88.86.

Olympic champion Denis Gargaud Chanut of France was second in 90.22.

Britain’s Ryan Westley picked up a two-second penalty for a gate touch but still did enough to qualify in third.

"I was not paddling in the Rio Olympics, I was sitting in the crowd watching the race," said Martikán. 

"I dreamed that I would like to paddle at the Olympic Games at this course. 

"It's always special because the Olympics is the best we can paddle at this most beautiful sport in the world.

"I was surprised about the result today, but I was not surprised by the run.

"After our eighth consecutive gold medal in teams' events yesterday, my feelings are very good and it’s the main reason why I was paddling so smooth today."