Olympic gold medallist Audley Harrison has announced his retirement from professional boxing.
The 41-year-old was knocked out by American Deontay Wilder after just 70 seconds in Sheffield on Saturday.
"I've done well to turn my life around, but sadly my dream to be a legitimate world champion will be unrealised," he said.
Harrison ends his career with seven defeats in 38 fights since winning gold as an amateur in Sydney 13 years ago.
He became the first British fighter to clinch an Olympic title in the super-heavyweight division but failed to build on that promise in the professional ranks
Total fights: 38
Wins by KO: 23
Gold medals: 2 (Sydney Olympics 2000
and Kuala Lumpur Commonwealth
The Londoner first challenged for the world title against David Haye in 2010 but suffered a third-round defeat.
His career looked to be over last October when he was knocked out in the first round by fellow Brit David Price.
But he won a Prizefighter tournament in February to keep alive his dream of one day winning a heavyweight world title.
However, Alabama's Wilder, who won a bronze medal at the 2008 Olympics, shattered that dream in little over a minute at the Motorpoint Arena on Saturday.
"There are only so many times you can fall before it becomes foolhardy to continue," Harrison said.
"I've fallen a lot, but winning the heavyweight title was a destination I really wanted to get to. Coming back from adversity has been synonymous with my life.
"I believed if I was mentally and physically right, I could figure these young guns out. Saturday was my final chance to prove it.
"The thing that pulled me up was pride, so I wanted a chance to continue and go out on my shield. It was not to be."