Ricky Hatton knows full well just how hard Manny Pacquiao at the peak of his legendary boxing powers.
British icon Hatton got to feel the forces of some of the greatest fighters of the modern era, including Floyd Mayweather, Kosta Tszyu, and Jose Luis Castillo.
And he also earned the rare opportunity to meet legendary multi-weight champion Pacquiao in a classic contest in 2009.
'The Hitman' was coming into the twilight stages of his career, but fancied his chances against the elite level Filipino.
He took his army of fans to the iconic MGM Grand in Las Vegas, smelling an upset from the first bell.
But he was met with an incredible display of power and brilliance from the iconic character, who burst out of the traps.
Hatton found himself in a world of pain, dazed by booming shots which saw him eating the canvas twice in the opening period.
He managed to compose himself and return to his feet showing a real warrior streak, but what unfolded would shake the boxing world for good.
Pacquiao dropped a bomb of a left hook which landed flush on the Briton's chin, with just five seconds until the final bell.
And it left Hatton motionless out cold on the canvas, and was considered one of the most devastating KOs in boxing history.
The victim of the ferocious shot Hatton, has opened up to talkSPORT.com about the punch, insisting it was the hardest of his life.
But he also admits he doesn't even remember it landing, and is simply imagining the power behind it was sensational.
"When I fought Manny Pacquiao, I was a little bit past my sell by date. Pacquiao was knocking everyone out at the time.
"It was a very brutal KO, so I'd probably say that one [is the hardest punch] even though I wasn't at my best.
"The thing is with that Pacquiao punch, I was completely out cold. So you can't in many ways even really remember it.
"I've had a few fights where I've had to back myself up and bite down and get through it.
"But the Pacquiao KO was one of the most devastating fights in history, so I'd have to say that one."
Hatton's taxing blow left a real mark on the end of his career.
The Mancunian made just one more appearance after recovering from the devastating KO, a farewell which also ended in stoppage defeat to Vyacheslav Senchenko three years later.
Pacquiao went on to fight for 12 years to come, with his longevity in the sport simply remarkable.
But at the age of 46 his best years are now behind him, albeit he doesn't agree.
The Filipino has not fought since 2021, but will incredibly return in a world title fight against Mario Barrios on July 19.
He has even be reinstated in the WBC world rankings at No.5.
And Hatton has been left shell shocked by the news.
He added: "Boxing is very very strange these days.
"If Mike Tyson can come back at 58, Pacquiao can come back.
"But I'm surprised it's for a world title, he's had so many years off and he's 46.
"He's getting the shot because of his history or whatever. Not saying he isn't capable of winning, but boxing has changed so much."
