Ricky Hatton faces Floyd Mayweather for the American's WBC welterweight crown in Las Vegas in the early hours of Sunday morning.
BBC Sport asked Britain's other six world champions what Hatton means to boxing in this country and whether he can pull off a famous victory at the MGM Grand.
Joe Calzaghe, undisputed world super-middleweight champion
"If Ricky wins it's going to be absolutely amazing. I'm going over and I'm going to be rooting for Ricky.
"I think he's got a great chance. I've spoken with Ricky, I know he's really trained and he's stronger than he's ever been.
"The heart wants Hatton to win but my head says Mayweather because he's an amazing fighter. But Ricky pulled it off against Kostya Tszyu and I think he may be the hungrier for this fight."
David Haye, undisputed world cruiserweight champion
"Ricky Hatton and Joe Calzaghe are by far the most accomplished British fighters of all time. But particularly Hatton, and if he could beat Mayweather, I'd say he's the most successful British boxer of all time.
Ricky's putting British boxing on the map and keeping it in the headlines. Every time he fights it's a major event.
He's been a massive inspiration in my career. I was still an amateur when Hatton was a world champion, still learning my trade. Now to be alongside them as one of Britain's three undisputed world champions, it's a nice feeling.
I take Ricky on a unanimous decision, maybe by one point on all the cards. I've watched all their fights and Ricky's style is a nightmare for Mayweather.
Mayweather won't like the pressure, he'll be unsettled. Mayweather is used to being in the comfort zone and fighting at his own pace. Also, Hatton is naturally bigger and people underestimate his speed. He's not as fast as Mayweather, but fast enough to make a big impression."
Enzo Maccarinelli, WBO cruiserweight champion
"At the moment we've got two modern greats in Ricky Hatton and Joe Calzaghe and they rank highly among the all-time great British boxers. If Ricky were to beat Floyd Mayweather, he could be regarded as the greatest ever.
Ricky has a style Mayweather won't like to fight against. Ricky is all-out aggression, and as Oscar de la Hoya showed, Mayweather doesn't like it when you don't allow him space. But De la Hoya faded towards the end, which is something I don't expect Ricky to do.
Until recently I would have said Floyd Mayweather to win all day long, but over the last couple of months Ricky has been oozing confidence and I see him stopping Mayweather after nine or 10 rounds.
He's relentless and he'll wear Mayweather down. Jose Luis Castillo put Mayweather under pressure, but not like Ricky will. It would be a shock and Mayweather's camp have labelled him one-dimensional, but Ricky can fight."
Gavin Rees, WBA light-welterweight champion
"Ricky is in with a real shout. I'm looking to him to work non-stop and take away Mayweather's spirit and edge by attacking him to the body.
"This is the fight the world wants to see and I'm sure Ricky has the ability to be the one to walk away with his record intact. Hatton has been hit by top liners and shown that he has a good solid chin."
Junior Witter, WBC light-welterweight champion
"Ricky's definitely in the mix with Britain's greatest ever. He's not the most technical or skilful of boxers, but he's got a big heart, a good work-rate and you can't deny what he's done.
He's been important for British boxing in many ways. After Naseem Hamed, British boxing was looking for a superstar and he fell into that niche. He has a style people can identify with - he's less flashy than Naz or myself, easier to read.
If he beats Floyd Mayweather, you'd have to put him up a few more pegs. Floyd Mayweather is the best pound-for-pound fighter in the world, so if he beats him, it will be one hell of a victory, he couldn't really do any more to please the British public.
It would be great if he did pull it off, but I don't think he will. The skill and power with accuracy that Mayweather brings will be too much.
I think Ricky will come out and trouble Mayweather for the first few rounds before Floyd finds his rhythm and takes him apart. I think it will be a stoppage on cuts or a landslide points victory."
Clinton Woods, IBF light-heavyweight champion
"Ricky's got to be up there with Britain's best of all time. Him and Joe Calzaghe have done more for British boxing than any other fighter.
If he beats Floyd Mayweather he'll probably go down as the best British fighter ever because Mayweather's probably the best fighter now and probably one of the best ever.
But Ricky's got a massive task ahead of him. He can win it, but I think Mayweather's fought better fighters and beaten them a lot easier than Ricky.
Mayweather struggled against Oscar de la Hoya, so if Ricky can pressure him like De la Hoya did, then maybe he's got a chance. But is Mayweather going to find him easy if Ricky tries to swarm him?
Mayweather's fought people like Ricky before, come-forward fighters, and he's played with them. Remember what he did to Arturo Gatti? Remember what he did to Carlos Baldomir?"