Olga Butkevych apologised for her performance as her Olympic dreams evaporated in to thin air after just six minutes.
Ukraine-born Butkevych was expected to reach the quarter-finals but Britain's first Olympic wrestler crashed out in the first round of the -55kg freestyle after an agonising defeat to Lissette Alexandra Antes Castillo.
Butkevych, who came to Britain in 2007 and gained citizenship in May, received a huge reception as she took to the mat at the ExCeL, but she was unable to deliver a win for the 10,000 rowdy fans in the arena on London's Docklands.
The 26-year-old lost a tight first period, but clinched the second to increase her hopes of victory.
Those hopes were dashed in the most agonising fashion soon after, however, as her 21-year-old opponent pushed her off the mat with just four seconds of the final round left.
"I'm sorry, I'm sorry," a tearful Butkevych said afterwards.
"It's my big competition, once every four years. I've been competing every year for the past four years.
"But this year, the big year, I lost. I didn't feel pressure from the crowd, but I was proud to be there for them.
"There were so many people here to support me and I'm proud but sorry."
Questions will now be asked about British Wrestling.
The body, who received £1.4million in funding over the last four years, were tasked with producing three Olympic-level wrestlers, but only Butkevych made the cut after the other two athletes ear-marked for a place in the squad failed to reach their targets.
UK Sport also challenged British Wrestling to produce one top-eight finish at the Games, but Butkevych's first-round exit means the body fell well short of that target.
The fact that Butkevych was selected despite not being born in Britain has also caused some unease, but British Wrestling's performance director Shaun Morley brushed off suggestions that the 26-year-old should not have been representing Team GB, and insisted the future is bright for the sport in the country.
"I think it was obvious to everyone that Olga has got the quality to compete at that level, those questions are ridiculous," he said.
"I think Olga just has to learn from the experience and move on to the next level.
He added: "At the end of the day we have spent the last four years starting to develop a programme and that is starting to come to fruition.
"I'm hoping that a lot of young kids will take inspiration from Olga, and the rest of the team here today, and come in to the sport and hopefully in four years' time we will have someone who can compete for a medal."
It is unclear whether Butkevych will carry on wrestling in the hope that she will make Rio 2016.
She had to sweat off four kilograms to compete today as there is no -59kg category in the Olympics and she feels that may have been one reason why she lost.
She added: "Maybe I've lost too much weight and she was too strong for me. I lost the challenge and I'm so upset.
"I'm disappointed. I felt like it was definitely my match and I should have won, but that's sport.
"I still don't know what happened. My body was shaking more and more."
Japan's Saori Yoshida will face Canada's Tonya Lynn Verbeek in the final of Butkevych's weight division this evening.
Tonight's other final sees Natalia Vorobieva of Russia take on Bulgaria's Stanka Zlateva Hristova in the heavyweight division.