Floyd Mayweather Jr is taking his unbeaten mark into the ring against Manny Pacquiao. Boxing's richest fight has been talked up from various aspects and fans will have their views on all the hype. This is as good a time as any to go down memory lane and revisit six of the more memorable bouts in the history of boxing.
Max Schmeling v Joe Louis (New York City, 1936)
Unmistakable political overtones hovered over the heavyweight bout as German Schmeling took on Louis at Yankee Stadium. It took only four rounds for Schmeling to send Louis to the canvas, a career-first for the African-American boxer.
Louis regained his feet but Schmeling continued to dominate, and in the 12th round landed a vicious blow to the jaw that sent Louis down for the count.
It was the first time the Brown Bomber had been knocked out, and 15 years passed before it happened again. Louis gained revenge with a victory in a rematch two years later.
Quote - "For the wonderful victory of your husband, our greatest German boxer, I must congratulate you with all my heart," German Chancellor Adolf Hitler, in a congratulatory message to Schmeling's wife.
Joe Frazier v Muhammad Ali (New York City, 1971)
What came to be known as "the Fight of the Century" was a brutal battle of attrition, but both men were still standing, Ali only barely, after 15 rounds.
Ali started strongly but Frazier got on top as the fight progressed and by the end was clearly ahead on points. Ali, battered and bruised, was knocked down in the final round but regained his feet in time to avoid a knockout. Nevertheless, he lost in a unanimous decision, his first defeat as a professional.
Three years later, Ali won a rematch in a non-title fight, before another more famous victory over Frazier in the "Thrilla in Manila" in 1975.
Quote - "No one can hit as hard as Frazier," Ali said after their first fight.
Muhammad Ali v George Foreman (Kinshasa, Zaire, 1974)
Ali was the underdog for what turned out to be a classic fight in the central African country now known as Democratic Republic of the Congo.
Foreman, at the time the undefeated world heavyweight champion, delivered numerous blows to Ali's abdomen, but Ali absorbed the punishment. Foreman, at 24 eight years younger than Ali, could not deliver a significant head blow to his opponent, and Ali bided his time in the steamy tropical heat, adopting a "rope-a-dope" strategy of staying on the ropes and conserving energy as he waited, hopefully, for Foreman to tire.
Late in the eighth round, Ali launched himself off the ropes and unleashed a furious attack to Foreman's head, sending him to the canvas to win in a knockout.
Quote - "You could hear the referee counting ... By the count of 10, my whole life was devastated," Foreman recalled years later.
Sugar Ray Leonard v Thomas Hearns (Las Vegas, 1981)
In this unifying welterweight title bout between two all-time greats, Hearns was ahead on points late in the fight, and Leonard knew he needed a knockout to win.
In the 14th round, Leonard unleashed a furious barrage of punches that left Hearns reeling and prompted the referee to stop the fight and award Leonard victory.
Hearns was still ahead on points with all three judges. Eight years later a rematch ended in a controversial tie, though Leonard acknowledged later that Hearns should have got the decision.
Quote - "Every punch that he hit me with, from the body to the head, felt like bricks, stone, rocks. He knocked my teeth back ... because he was just so possessed. He was a demon." Leonard, on the punishment he endured from Hearns.
Marvin Hagler v Thomas Hearns (Las Vegas, 1985)
It was a short but memorable bout between the middleweights, who held nothing back in a frenetic first round.
The fight lasted less than three rounds, barely eight minutes of the most intense and brutal fighting, before Marvellous Marvin sent the Hit Man to the canvas. Hearns eventually struggled to his feet on the count of nine, but the referee stopped the fight.
Quote - "Even today when I look at the film, I'm so glad when that fight is over," Hagler said years later.
Buster Douglas v Mike Tyson (Tokyo, 1990)
Considered one of the biggest upsets in boxing history, Douglas was almost 50/1 against the then-undefeated heavyweight champion Tyson.
But what the bookies did not know was that Tyson had prepared poorly. Douglas took the fight to his more fancied opponent from the start.
However, it looked like order was being restored when Tyson sent Douglas to the canvas at the end of the eighth round. Douglas barely regained his feet in time to beat the count. He was saved by the bell.
Two rounds later he launched a series of devastating blows to Tyson's head, knocking down the champion for the first time in his career.
Quote - "I don't know how I thought I could have won. I wasn't training properly. I had it coming," Tyson said later.