Britain's David Florence could not hide his disappointment as he failed to make the final of the canoe slalom.
The world number one was a genuine gold medal prospect for Team GB having narrowly missed out on top spot in Beijing. He had already notched up two golds at this year's World Cup meetings and was hopeful of competing with France's Tony Estanguet and Slovakia's Michal Martikan for a medal.
There was only one run to qualify for Tuesday's final, and the 29-year-old from Aberdeen, who at one time toyed with becoming an astronaut, blew his chance. With the 12,000 capacity crowd cheering him on, he started well, recording the fastest split of the round over the first third of the course.
But then he over-rotated going in to gate 16, which forced him to take a bad line on the approach to gate 18, which he touched with his pole, and it was all but over by the time he crossed the line in 106.16 seconds, 0.7 seconds off what would eventually be needed to make it to the last eight.
Speaking afterwards, Florence - nicknamed D-Flo - could not hide his disappointment. He said: "I have wanted to perform at this event for the last four years and not to do so is very frustrating.
"But it's part of the sport of canoe slalom - some days it doesn't go your way. All I was trying to do was put in a great run the whole way and that is all I was really concentrating on. It's easy to say it was the pressure of the home crowd (that got to me) but this is a very up-and-down sport and today I wasn't good enough."
The racing was eventually won by Estanguet, the 44-year-old from Pau in south-west France. He suffered a similar disappointment to Florence in Beijing in 2008, finishing ninth.
But he dominated the field in the final run, comfortably beating the 22-year-old German Sideris Tasiadis - who regards the Frenchman as his hero - by just over a second. Martikan, 33, who already holds two golds and two silvers from previous Games, took the bronze, admitting he was a little disappointed at the result.
Florence must now turn his attention to the two-man canoe semi-final on Thursday, where he will be joined in the boat by Richard Hounslow, the 30-year-old paddler from Loughton in Essex.
John Anderson, performance director at Team GB canoeing, said Florence would be able to bounce back quickly. He said: "David will obviously do some reflection on that run because obviously he has the C2 to come in two days' time. He is such a professional that he will refocus and put everything he has in to the C2."