Manny Pacquiao paid tribute to "a great fighter" and "a brave and kind man" following the death of his former opponent Ricky Hatton.
Pacquiao, whose stunning second-round knockout of "The Hitman" in Las Vegas in 2009 marked the start of Hatton's decline at elite level, said he felt "blessed to have been part of his wonderful journey."
The Filipino former eight-division world champion posted on Instagram: "I am deeply saddened to hear about the passing of Ricky Hatton. He was not only a great fighter inside the ring but also a brave and kind man in life.
"We shared unforgettable moments in boxing history and I will always honor the respect and sportsmanship he showed. Ricky fought bravely, not just in the ring, but in his journey through life. He truly had a good fight, and we are all blessed to have been part of his wonderful journey.
"My prayers and deepest condolences go out to the Hatton family and all his loved ones. May the Lord give you strength and comfort in this difficult time. May he rest in peace."
Pacquiao's former trainer Freddie Roach recalled: "Ricky had a wonderful sense of humour, but more importantly he was a warrior and a winner. There will be only one Ricky Hatton."
Hatton's former promoter Frank Warren said the Brit was a "modern great" who deserves his place among the best of boxing history.
Warren managed Hatton's career from his professional debut in 1997 up to his historic world title win over Kostya Tszyu in 2005.
Warren wrote on X: "I am extremely saddened to learn of the passing of British boxing legend Ricky Hatton.
"A superbly talented fighter who inspired a generation of young boxers and fans in a way very few had done before due to both his personality and the entertainment he provided in the ring.
"From making his debut Widnes in 1997 to then go on to win one of the most historic fights in British boxing history against Kostya Tszyu in Manchester, Ricky will rightly go down as one of the modern greats of this sport."
Fellow promoter Eddie Hearn also paid tribute on X, writing: "Everybody loved Ricky. May he rest in eternal peace. Our deepest condolences to [son] Campbell, [brother] Matthew and all of the Hatton family."
Amir Khan, another former world champion and a friend of Hatton, described him as a "mentor, warrior and one of Britain's greatest boxers."
Writing on X, Khan said: "Today we lost not only one of Britain's greatest boxers, but a friend, a mentor, a warrior, Ricky Hatton."
Over recent years, Hatton had been open about addressing his mental health, and Khan added: "As fighters, we tell ourselves we're strong -- we train, we sweat, we take hits, we get up. But sometimes the hardest fight happens in silence, in the mind.
"Mental health isn't weakness. It's part of being human. And we must talk about it. We must reach out. We must lean on each other.
"Ricky, thank you for everything. For your fights, your moments of glory, your grit. Thank you for pushing us, showing us what's possible.
"To everyone reading this: if you're hurting or struggling, you are not alone. Talk. Reach out. Because we need more light, more compassion, more understanding.
"Rest well, Ricky. You'll always have your place in the ring of our memories."
Britain former world heavyweight world champion Tyson Fury also paid tribute.
Alongside two pictures of him with Hatton, Fury wrote on Instagram: "Rip to the legend @rickyhatton may he rip. There will only ever be 1 Ricky Hatton. Can't believe this so young."
Chris Eubank Jr. wrote, "Rest in Peace Mr Ricky Hatton. We salute you", while Turki Al-Sheikh, one of the sport's most high-profile promoters, said: "I am saddened by the tragic news of Ricky Hatton's passing at the young age of 46.
"He was a great fighter and a legend in British boxing."
Matchroom Boxing said: "[We are] saddened to hear the news of Ricky Hatton's passing. Our thoughts and condolences are with Ricky's friends and family at this tragic time. There's only one Ricky Hatton."
British Olympic gold medalist Luke Campbell said Hatton was an "inspiration to him" and a "legend in the world of boxing."
Hatton was synonymous with his beloved Manchester City and the news of his death came ahead of the Manchester derby.
- City superfan Hatton remembered before Manchester derby
Speaking on Sky Sports, ex-City defender and broadcaster Micah Richards said: "The news is devastating. He's such a British icon ... A true Man City fan, but most importantly he was a man of the people.
"He was the nicest guy ever -- I remember going down to one of his gyms and I was a bit nervous because I didn't know about boxing and he said 'just do this' and he took his time.
"For him to take the time and effort, I've been multiple times for beers with him just talking about football and life. To get this news now is just surreal."
Sixteen-time former world darts champion Phil Taylor posted: "Absolutely devastating news about the passing of my mate @HitmanHatton Thoughts go out to all of his family at this horrible time. RIP my friend."
Information from PA contributed to this report.
