During a career that spanned five decades, Roberto Duran earned the nickname "Manos de Piedra" ("Hands of stone") thanks to his destructive punching power and the fact that he was raised in the slums of El Chorrillo in the district "La Casa de Piedra" ("The House of Stone"), in Panama City.

Buster Douglas was a 42-to-1 underdog going into his 1990 fight against Tyson, who was undefeated and considered to be the best boxer in the world for his domination of the division over the previous three years. Defying expectations, Douglas knocked Tyson out in the 10th round to claim the WBC, WBA, and IBF titles.

In 1949, there was an official boxing match between Gus Waldorf and a muzzled bear. The match was conducted under surveillance of professional judges. The bear won.

The Rumble in the Jungle has been called "arguably the greatest sporting event of the 20th century." It was a major upset victory for Ali who came in as a 4-1 underdog against the heavy-hitting Foreman. The fight is notable for Ali's introduction of the rope-a-dope tactic, letting Foreman land body blows in order to tire him.

Mayweather went his whole career without being knocked out, but there was one time he was technically knocked down. In 2001, the 43-year-old Mayweather took a count in a bout against Carlos Hernández. It occurred in the sixth round after Mayweather clocked the Salvadoran fighter with a left hook. Mayweather moved his hands to the canvas, complaining about his hand which ended up being ruled as an official knockdown for Hernández.

In 1994, at age 45, George Foreman became the oldest heavyweight champion in history when he knocked out 27-year-old Michael Moorer to win the unified WBA and IBF titles.

Canadian boxer Tommy Burns was just 5 feet 7 inches (170 cm) tall and about 175 pounds (79 kg), but that didn't stop him from becoming the World Heavyweight Boxing Champion or defending his title eleven times. According to his biographer, Burns insisted, "I will defend my title against all comers, none barred. By this I mean white, black, Mexican, Indian, or any other nationality. I propose to be the champion of the world, not the white, or the Canadian, or the American. If I am not the best man in the heavyweight division, I don't want the title."

In 1876, at Harry Hill's Variety Theater in New York, the first known women's boxing match took place between Nell Saunders and Rose Harland. Saunders received a silver butter dish as a prize.

A southpaw, Hungarian boxer Laszlo Papp won gold medals in the 1948 Summer Olympics in London, the 1952 Summer Olympics in Helsinki, and the 1956 Summer Olympics held in Melbourne, Australia. There would not be another triple gold medalist for 20 years, until Teofilo Stevenson won three (1972, 1976, 1980), followed by Felix Savon (1992, 1996, 2000).

According to Roberto Duran, he once knocked out a horse after someone bet him a bottle of whiskey that he couldn't do it. "I didn't know where to hit the horse," he said, "it didn't seem to have a jaw. But my uncle, Socrates, told me to catch it just behind the ear and down it went. I ripped my hand open. You could see right down to the bone. But I was too drunk to feel it and I won the bet."