Halesowen cycling star Jess Varnish's bid for Olympic glory ended in heartbreak with disqualification from the women's team sprint.
Varnish and team-mate Victoria Pendleton were eliminated for an illegal changeover during their second ride which denied them a place in the final.
The duo had earlier sent the velodrome into raptures when they set a new world record in their first ride, which was then almost immediately broken by China in a thrilling contest.
Further drama followed later in the final as Germany claimed gold despite finishing second, as the China were also disqualified for an illegal change.
For the thousands packed into the velodrome and the dozens crammed into Halesowen Cycling Club, this was not the result anyone wanted or even expected.
On the day the British duo found themselves with superior speed to favourites Australia and world champions Germany, only to lose out on a shot on a gold medal showdown with China by what proved to be inches.
Television replays showed Pendleton’s front wheel had edged ahead of Varnish’s before the end of the first lap, a breach of the rules which meant relegation to eighth position.
It had all started so well. Varnish and Pendleton had began in blistering style, smashing the world record on their first ride with a time of 32.526 and leaving Australian rivals Anna Meares and Kaarle McCulloch trailing in their wake.
The scene then seemed set for a dramatic evening as China's Jinjie Gong and Sheung Guo broke the new standard in the very next heat, posting 32.447.
It was a similar story in the next round, China fastest and Britain second. Varnish and Pendleton looked to be guaranteed at least silver.
But the mood changed dramatically when it emerged the officials were investigating the British changeover on the second ride.
Following a long and often confusing 15 minutes, their elimination was confirmed to leave Varnish's dream in ruins.
Speaking afterward, Pendleton admitted the error was difficult to explain.
She said: "It's really hard when you are going at that speed, if Jess moves up slowly I just go.
"It's just one of those things which happens, it's not Jess' fault, it's not my fault, we are both partly to blame really.
"We were probably a bit overwhelmed by the whole thing and a bit over-eager. We should have kept a lid on it really.
"Now and again rubbish things happen and this is one of those times."
Varnish will not ride again in these Olympic but Pendleton, who retires at the end of the Games, had comforting words.
She added: "She will have many more Olympics to go to I'm sure. It's the end for me but just the beginning for Jess."
The officials were then further involved later in the final, with Chinese duo Gong Jinjie and Guo Shaung eliminated in what looked a very marginal decision.
That handed victory to German world champions Miriam Welte and Kristina Vogel, who were informed of their promotio to gold by BBC reporter Jill Douglas amid the confusion.