Great Britain's Craig Brown was predictably downbeat in defeat after his dream of Olympic debut gold was shattered by Australian Daniel Trenton.

The 21-year-old, competing in the under-80kg class, failed to reach the quarter-finals after losing out 12-6 to his impressive Australian opponent, who was a silver medallist in Sydney four years ago.

It was a brave performance from Brown, who only two years ago could not even compete at the World Championships in Turkey due to a lack of international experience - even though he was the British number one.

The Londoner recovered from a broken shoulder and wrist and the loss of his father to cancer earlier this year to claim his place in the Team GB taekwondo squad for Athens.

To make his bid for glory even more difficult, the British champion was handed an extremely tough draw in his first match against the experienced Trenton, a fighter six years his senior.

Brown admitted the draw had not been kind to him and despite insisting he would leave Athens with no regrets, his youthful enthusiasm did nothing to hide his disappointment.

"It is one of the toughest draws but it's the Olympics," he said.

"I could have hoped for a better draw with an easier fight to start, and then after that I might have got going but it wasn't to be.

"I only started fighting internationally three and a half years ago, so I'm the newest to the squad out of all of us, but I still think I could have done a lot better.

"He's a good fighter, all credit to him because he was sharp today, but I'm sure I could have beaten him at my best."

Brown said low energy levels were to blame for his defeat but could not put his finger on why he was lacking in that department.

"I'm not sure what it was, I just felt short of energy, I don't know if it was dehydration or whatever but I just didn't feel my normal self out there," said the 21-year-old.

"I was fairly confident going into it because I've fought some of the best people in the world before and I've done well against them. It just wasn't my day today.

"I gave my best, I couldn't have done any more. I can't come out of there having any regrets saying 'I should have done this or that' I just had no energy."

Brown denied the fact that he was competing in his first Games was a factor.

"I think I coped quite well with the atmosphere. I don't think that was to blame," he added.

"I just think I ran out of steam. It's good for me to feel that I could go out there though and I didn't let the occasion get to me."

Although he lost, Brown still had hopes of earning the right to compete for a bronze medal in the repechage competition as long as Trenton reached the final.

It was not to be though as Trenton crashed out in the quarter-finals, losing 13-9 to Iran's Yosef Karami.

It is now a case of three down, one to go for Team GB's taekwondo squad after the exits of Paul Green, Brown and Sarah Bainbridge today.

Green lost in the quarter-finals of the under-58kg category on Thursday with Brown and Bainbridge, who lost to Holland's Charmie Sobers, crashing out in the round of 16 today.

Britain's last hope of a medal lies with Sarah Stevenson, who will fight on Sunday in the women's over-67kg class.

The 21-year-old former world champion narrowly missed out on a bronze medal in Sydney four years ago and has been on top form since returning from knee surgery in 2003.