10. Harry Greb
Ring career: 1913-26 Record: 105-8-3 (48 KOs) and 183 no-decisions
By comparison to some in his era, Greb had a relatively brief career but packed so much into it, winning the world middleweight title in 1923 and defending it six times over the next three years. In 1922, he became the only boxer to defeat future heavyweight champion Gene Tunney – the man who dethroned the great Jack Dempsey
9. Benny Leonard (Right holding back Harry Houdini centre)
Ring career: 1911-32 Record: 85-5-1 (69 KOs) and 121 no-decisions
Leonard won the world lightweight title in 1917 and retired as champion in 1925, making him the longest-reigning lightweight champion in history. After more than seven years he returned to the ring, winning 18 of his 19 bouts. Indeed, at one stage he had gone 154 fights without defeat.
Of five losses, three were in his formative ring years, one was on a foul when challenging for the welterweight championship and one was the final contest of his caree to fellow legend Jimmy McLarnin. He later became a referee and collapsed and died in the ring while refereeing a bout. (Everett/REX Shutterstock 908752a)
8. Manny Pacquaio
Ring career: 1995-present. Record: 57-6-2 (38KOs)
Named Fighter of the Decade for the 2000s by the Boxing Writers of America, Pacquaio is the first boxer to win world titles in eight divisions – starting with the WBC flyweight title. A huge hero in the Philippines, his homeland comes to a standstill to watch their hero in action. A phenomenal athlete, he holds wins over legends such as Marco Antonio Barrera, Oscar De La Hoya, Erik Morales and Shane Mosley on the way from flyweight to welterweight glory. (Photo by Chris Hyde/Getty Images)
7. Floyd Mayweather Jr Ring career: 1996-present. Record: 49-0 (24 KOs)
Mayweather's place in an all-time top 10 may well be disputed by many who find it hard to appreciate his style which is founded on a slick defence. But the Noble Art is about hitting and not being hit and Mayweather fits that mould perfectly. From super-featherweight through to light-middleweight he has thwarted numerous great fighters, including Manny Pacquiao, Oscar De La Hoya, Shane Mosley and Saul 'Canelo' Alvarez. (Al Bello/Getty Images)
6. Roberto Duran
Ring career: 1968-2001 Record: 103-16 (70 KOs)
Won the lightweight World title from Ken Buchanan in 1972 and then proceeded to dominate the division for seven years with his ferocious intensity and smart boxing skills. Duran would then lift the welterweight title when he outpointed Sugar Ray Leonard in 1980. Five months later he lost to Leonard but would go on to win the light-middleweight title three years later and in 1989 produced an amazing performance to outpoint Iran Barkley and land the WBC World super-middleweight crown
5. Sugar Ray Leonard
Ring career: 1977-97 Record: 36-3-1 (25 KOs)
Leonard managed to stand out in an era of legends, winning great fights against Roberto Duran, Thomas Hearns and Marverlous Marvin Hagler. The 'Four Kings' as they would come to be known, captured the sporting world in the early 1980s. Leonard won the WBC World welterweight title before unifying the division with a stoppage of Hitman Hearns. He would go on to win world titles at light-middle, middle, super-middle and light-heavyweight. Famously, having lost to Duran in an epic brawl, he forced the Panamanian to quit in their re-match, forever known as the 'No Mas' fight. (Mike Powell/Allsport)
4. Muhammad Ali
Ring career: 1960-81 Record: 56-5 (37 KOs)
Ali transcended the sport unlike any other boxer and was for many the greatest sportsman of the 20th Century. His speed and grace in the ring for a heavyweight were a sight to behold and even when the footwork was slowing down he had the fortitude to stand up to awesome punchers like George Foreman, Joe Frazier and Ken Norton in the 1970s. The first man to win the World heavyweight title three times, his first reign came when as a 7-1 outsider Ali stopped Sonny Liston in 1964. He regained the title 10 years later with his epic victory over Foreman in 'The Rumble in the Jungle'. Lost and then defeated Leon Spinks in 1978 to win the title for a third time. (Trevor Humphries/Getty Images)
3. Willie Pep (R)
Ring career: 1940-66 Record: 230-11-1 (65 KOs)
The two-time world featherweight champion was renowned for his defensive skills, enjoying amazing success despite suffering near-fatal injuries in a plane crash in 1947. Known as Will o' the Wisp, Pep won his first 63 fights before losing to Sammy Angott, and then went 72-0-1 before losing again to Sandy Saddler with whom he had four epic encounters.
2. Henry Armstrong (L)
Ring career: 1932-45 Record: 151-21-9 (101 KOs)
Armstrong is the only boxer to hold world titles at three different weights simultaneously. In an age when there was only one world champion and just eight weight divisions, he won the featherweight title crown in October 1937 before winning the welterweight title in May 1938 and became lightweight champion three months later. Dubbed Homicide Hank, he also fought for the world middleweight title in 1940, holding Ceferino Garcia to a draw. In all, he faced 17 world champions and defeated 15 of them. (ANL/REX Shutterstock 1381703a)
1. Sugar Ray Robinson
Ring career: 1940-65 Record: 175-19-6-2 (109 KOs)
Born Walker Smith, he would go on to become the supreme ring combatant, Sugar Ray Robinson, winning World titles at welterweight and middleweight. The welterweight title came in December 1946 and he defended it four times before stepping up to middleweight on the back of a solitary loss in 124 bouts. He would become a five-time world middleweight champion, defeating such legends as Carmen Basilio, Jake LaMotta and Gene Fullmer.
His only stoppage defeat came when losing to Joey Maxim for the world light-heavyweight title – a bout fought in such extreme heat that the referee had to be replaced in the 10th round. (Allsport Hulton/Archive)
Our boxing specialist, David Kelly, brings you his top 10 professional fighters of all time, including legends Muhammad Ali and Sugar Ray Robinson.