Derwent Canoe Club member Daniel Watkins finished in ninth place in the C1 final at the Tokyo Olympics.
The Oceania champion couldn't reproduce his semi-final heroics as he incurred a two-second penalty and recorded a time of 108.18, nearly 10 seconds behind gold medal-winning Slovenian Benjamin Savsek.
"One really big mistake," Watkins said.
"It's a little bit annoying because I was pretty good through the top and after I got back from that mistake the arms were burning and I wasted 10 seconds paddling away from the finish line basically.
"I still held it together and had a good finish so I've got to be happy with that. Take out the middle and I was mostly performing under stress, so that's good."
I had a good finish so I've got to be happy with thatDaniel Watkins
Earlier, Watkins had stunned the competition by qualifying second fastest for the final.
Having needed a second run in the heats on Sunday to progress, the Grove 25-year-old came alive in the semi-final, recording a time of 101.28, bettered only by Frenchman Martin Thomas.
A beaming Watkins was punching the air after completing what Channel Seven commentator Dave Culbert called "the run of his life" at the Kasai Canoe Slalom Centre
Analyst Richard Fox added: "That was sensational because he had to keep his cool, make the right choices, was he going to spin, go direct, time switches from left to right adding complexity, but he turned it to his advantage, kept his cool and that's so good."
Also selected as a reserve for K1, Watkins, who has a decade of international experience in canoe and kayak racing, prepared for a maiden Olympic Games by contesting world cups in Prague and Leipzig before a week at the Paris venue which will stage the next Olympic competition in 2024.
He said he would take time to reflect on his achievement and enjoy the moment of becoming an Olympian.