Nick Blackwell has woken from his induced coma, following his fight with Chris Eubank Jr last week.
The 25-year-old was taken to hospital after the British middleweight title contest was stopped in round 10.
Blackwell woke from the induced coma on Saturday and by Sunday was talking to family and friends at his bedside, said promoter Hennessy Sports.
Blackwell had suffered a bleed on the skull and not the brain as initially reported, the statement added.
Hennessy Sports said the boxer had won his "toughest fight yet", adding: "Nick Blackwell won the hearts of over three million television viewers on 26 March with an astonishing display of all-action bravery and determination.
"In the past week, however, he has humbled millions more. He's a fighter. He's a warrior. He's a true champion and gentleman.
"On behalf of Nick, his family, and very close friends, we'd like to thank everyone for their continued support and well-wishes. It has been overwhelming at times and has certainly not gone unnoticed."
Referee Victor Loughlin stopped the fight on the advice of the ringside doctor, who said Blackwell was unable to continue because of swelling over his left eye.
It meant Eubank Jr, 26, took the British middleweight title.
After the fight, Blackwell received medical attention in the ring before being taken away while receiving oxygen.
The British Boxing Board of Control said it was satisfied with the way the fight was handled.
Respected trainer Adam Booth told BBC Radio 5 live Loughlin had "acted immaculately", while former world champion Barry McGuigan, now a promoter, said it was an "isolated incident" and "nobody was to blame".
- Read: Referee 'immaculate' in Blackwell fight
- Listen: BBBC satisfied with how fight was handled
- Watch & read: I would have stopped the fight - Eubank Sr
- Read: Swelling may have saved Blackwell's life - Oliver
Eubank Jr posted a video to social media speaking of his "relief" after hearing the news of Blackwell's recovery. "The last thing you want is a fighter go through any serious damage," he said.
McGuigan added: "So delighted that Nick Blackwell has come out of his induced coma and is speaking to his family."
Those sentiments were echoed by fellow boxers Enzo Maccarinelli, Paul Smith Jr and Anthony Fowler.
Peter Fury, uncle and trainer of world heavyweight champion Tyson Fury and a friend of Blackwell's promoter, Mick Hennessy, said: "Great news Nick Blackwell has made a full recovery. Mick said he's smiling and talking, even telling jokes. In God we trust."
BBC boxing correspondent Mike Costello:
"Blackwell's progress will be the cause not so much of celebration but of relief across boxing.
"Long before he was placed in an induced coma, the 25-year-old was described as one of the most likeable characters in a sport which thrives on enmity.
"In the nine days since he collapsed in the ring at Wembley Arena, there's been a deluge of support from world champions and journeymen alike.
"His condition was a reminder of the risks they all take and the dangers they all face."
'A massive hole in his life'
Former super-bantamweight boxer Spencer Oliver suffered life-threatening head injuries in a European title fight in 1998, aged 22.
He was given oxygen by paramedics in the ring and, after 15 minutes of treatment, was taken to hospital apparently unconscious and wearing a neck brace.
The British fighter later had a blood clot removed from his brain and went on to make a full recovery, but retired from boxing.
Speaking on BBC Radio 5 live, Oliver said Blackwell's "biggest fight" now will be "coming to terms with not boxing again".
"A boxer's life is training, morning, afternoon and evening," said Oliver. "It's non-stop. He will have a massive hole in his life. I'd suggest putting something back into boxing, maybe getting into training."