A four-time world champion in the C1, her favoured event was included in the Olympic program for the first time, giving Fox the chance to make Games history.

Having started the K1 as a huge favourite and crossed for bronze due to a late error on course, it was feared Fox may struggle to come back from another stumble.

Her father Richard Fox, in television commentary, spoke of how "shattered" she was by the K1 result.

But this time three-time Olympian Fox wouldn't be denied, finishing 3.64 seconds clear of Britain's Mallory Franklin with Germany's reigning world champion Andrea Herzog taking bronze.

A beaming Fox splashed the water in delight before paddling to embrace her mother and coach Myriam Fox-Jerusalmi, who won bronze in the K1 event in Atlanta, and her sister Noemie.

Fox said she was thrilled to achieve her dream after the crushing disappointment in the K1.

"To come back after that was extremely hard, it was emotionally and mentally taxing. I'm so proud I was able to pull that run out," Fox told AAP.

"I was dreaming of it. I really believed it was all within me, that I could do it.

"You never know what's going to happen in the Olympics and it's about holding your nerve. I probably didn't do that in the kayak."

She revealed that despite her calm demeanour on course, matching that of father Richard as he calmly described her charge to victory, she vomited before the race through nerves.

"I've probably never been as nervous - 20 minutes before my race, even though I felt really good and calm I had a lolly and instantly I threw up and that's never happened to me before," she said.

"I think it showed how full on it was, but I'm so proud that I was able to do the run I wanted to."

Fox and her paddling family had long advocated for the race's inclusion on the Tokyo program, giving the sport gender parity.

She was one of just eight paddlers to do the C1-K1 double, with only one other qualifying for the final.

Fox said making history as the first Olympic gold medallist in the event was very special to her.

"I'm so proud to be in women's C1 category and of all the women who have raced here and been part of this moment," the Sydneysider said.

"I'm grateful to everyone who lobbied for gender equality and to have us here in this moment.

"I was in the warm-up pool when I heard the times the girls were putting down and I thought this is what I wanted.

"I wanted a great final, hot racing, and for me it was rising to that challenge. It has made the victory even sweeter."

Australian Associated Press