Jess Fox has underlined her standing as slalom canoeing's greatest paddler as she annexed a record-extending 14th world championship gold medal in spectacular fashion in London.

Australia's Olympic C1 champion was left celebrating an "emotional" triumph with her grandfather among the crowd at the Lee Valley White Water Centre after producing a remarkable run following a disastrous start in Saturday's kayak final.

It was her second gold of another triumphant week for Penrith's serial champ following her victory in the team event.

"I can't believe I've won today. It's amazing, I'm overwhelmed, so emotional," she said.

Fox, who had been fastest in the semi-finals and was last to go in the final, looked as if she might have cost herself victory right at the start of her run as she touched the first gate and incurred a two-second penalty.

It meant she would then have to deliver a flawless and daring run to surpass Slovakian leader Eliska Mintalova, who had also incurred a gate penalty.

"A bad word went through my head on gate one - but I held it together and, my goodness, it was a crazy race," beamed Fox.

After her early error, she did exactly what was required, flying through the rapids more than a second quicker than anyone else, taking the victory in a total time of 103.60sec, ahead of Mintalova's 104.73. Poland's Klaudia Zwolinska took the bronze in 105.00.

The Olympic and defending world champion in the event, Ricarda Funk, could finish only seventh.

"I really didn't start well, and then just really tried to attack it and take some risks and even until the last gate, it was it was very sketchy and I was nervous," said Fox.

"I knew it was a solid run, but you never know when you've got a touch earlier (in the run) whether you're up or not. So I just had to get my head down and finish strong. I was really pushing the lines and trying to be tight and give it everything I had.

"When I crossed the line, I didn't know if it would be enough and then I saw 'number one' - and pure joy! I'm just absolutely thrilled."

It was the 29-year-old Fox's 10th individual world championship crown, adding a fourth kayak (K1) triumph to her four canoe (C1) and two kayak cross victories but, remarkably, it was the first time she had won one of the sport's marquee global individual titles in C1 or K1 for five years.

"I had some family in the crowd. So it was really special to be able to go and give them a big hug," said Fox.

"My grandad was here and he stood up out of his wheelchair up at the top of the hill and I ran up to see him, so it definitely made me teary and emotional, being able to share it with them, share it with my teammates, it was super special."

Fox's victory - and a record-extending 22nd world championship medal - came just 24 hours after she had taken bronze in the canoe event on Friday.

And another triumphant campaign, 13 years after she won her first world medal in Slovenia and on the same Lee Valley course where she won her first Olympic medal in 2012, may not be over yet as Fox shoots for a third successive title in the kayak cross on Sunday.