Former world super-middleweight champion George Groveshas announced his retirement from boxing.
The 30-year-old has called time on his career four months after losing his belt to Callum Smith in September.
Groves, who is also known for two high-profile fights with Carl Froch, became world champion at the fourth attempt when he beat Fedor Chudinov in Sheffield in 2017.
The Londoner, who turned professional in 2008, said he wants to go out at the top.
"After taking a little time to reflect on the recent events in my career, I have decided that it is time for me to retire as a professional fighter," he said.
"In 2017, I boxed in front of a home crowd in Sheffield and became the WBA super-middleweight world champion.
"After four attempts I had finally fulfilled my childhood dream, and the experience was as great as I had always imagined it would be. It was without doubt the best moment of my career.
"Some of you might think it odd that I'm choosing this time to retire. I'm still young, still fit and healthy, and there are still some big fights out there for me.
"But it's for these reasons that I am choosing to retire now. I have a young family at home; it's time to spend some of my better days with them.
"I don't want there to be a time where I'm "too old" to box on, or where an injury retires me in or out of the ring.
"Over the years I have seen and sadly known the dangers of the sport, and I want to respectfully bow out while I'm at the top of my game.
"I've learned that doesn't always mean coming off the back of a win. I've boxed at the highest level, all over the world, I've been a champion, and I'll be leaving the sport (relatively!) intact.
"Boxing has been good to me and I believe I have been good for boxing.
"I hope I have entertained you all; I have always strived to be the best fighter I can be.
Having won his first 19 professional fights, Groves enjoyed a blockbusting clash with Froch in 2013 and was on course for a surprise dethroning of the WBA and IBF champion when the referee hastily intervened in round nine.
Groves won much public adulation, but lost the rematch with Froch again six months later at Wembley.
He finally got his hands on the belt in 2017 with a sixth-round stoppage of Chudinov at Bramall Lane and he defended that title twice before losing to Smith in Saudi Arabia last month.
In his fight prior to the Chudinov bout he beat Eduard Gutknecht and the German suffered a serious brain injury which left him in a coma and unable to fight again.
"Lastly a prayer for Eduard Gutknecht who suffered a brain aneurysm after our fight in November 2016," Groves added in a statement.
"He was put into an induced coma for three weeks and bravely fought his way back to consciousness. He lives in Germany with his wife, three children and a full-time carer.
"This fight brought home the realisation that boxing can have brutal consequences.
"After this, I truly felt like my fighting days were numbered. After winning the WBA world title I decided to only continue fighting while it felt necessary.
"After the birth of my second son last year and losing in the final of WBSS (World Boxing Super Series), I knew the desire to fight had left me.
"Retiring at 30 was a suggestion I first heard 10 years ago. I thought it was a good idea then and I still do now."