James DeGale has announced his retirement following his unanimous points defeat by Chris Eubank Jr.
The 33-year-old is a two-time world champion and 2008 Olympic champion and is the first British boxer to win both an Olympic gold medal and a professional world title.
DeGale said in a statement: "Today marks 10 years since my professional debut fight on February 28, 2009 and today is the day I am announcing my retirement from boxing.
"It's been an unbelievable journey and I've had an amazing decade – if I'm honest, the best years of my life."
DeGale rose to prominence after winning his first world title belt in the United States in 2015 against Andre Dirrell before defending it three times across the Atlantic.
He said: "It's hard to admit that I'm not the fighter I once was, but I'm human and along the way, my injuries have taken a toll – both on my mind and body and these things have contributed to my performance in the ring.
"I lost the fight on Saturday at the O2 but I'm touched to have a good send-off from the fans in my home city.
"I'm proud to say that I've made history as the first ever British Olympian boxer to turn professional and to win a world title and I am also proud to have been a road warrior – to travel wherever I needed to be to fight and win. There's nothing left to prove."
After beating Dirrell by a unanimous points decision in Boston in May 2015, southpaw DeGale claimed a unanimous victory against Lucian Bute in Bute's home state of Quebec, Canada.
Today he finishes as one of Britain's great boxers 🥊
— Team GB (@TeamGB) February 28, 2019
He made another successful title defence against Rogelio Medina in Washington DC in February 2016.
DeGale's bid to unify his IBF world super-middleweight title with Badou Jack's WBC crown ended in a draw the following January.
The Hammersmith-born fighter was then beaten by relative unknown Caleb Truax at the Copper Box Arena in December 2017 before winning his title back in April last year in a Las Vegas rematch.
DeGale finishes his professional career with 25 wins, three defeats and one draw.