Ingemar Johansson, the oldest living heavyweight champion, died late Friday in his native Sweden.
Johansson, 76, died from complications of pneumonia. He had been diagnosed with Alzheimer's disease several years ago.
Johansson had a brief professional career but a momentous one, with his rivalry with Floyd Patterson ranking as one of boxing's greatest trilogies.
A well-schooled upright boxer, Johansson had a good jab that helped set up a tremendous knockout right hand dubbed "Ingo's Bingo" and the "Hammer of Thor."
After earning a silver medal as a heavyweight at the 1952 Helsinki Olympics, the Gotheburg native defeated contenders such as American Eddie Machen and Henry Cooper of Great Britain to earn a heavyweight title shot on June 26, 1959.
Johansson made the most of the opportunity in the Yankee Stadium bout, scoring a whopping seven knockdowns of Patterson to win by third-round stoppage.
He became just the third European to win boxing's most coveted crown in the 20th century, following Max Schmeling of Germany and Primo Carnera of Italy.
The undefeated fighter was the toast of the sporting world, earning recognition as the Associated Press athlete of the year and the Sports Illustrated sportsman of the year.
The Swede's reign would last just under a year, however, with Patterson becoming the first man ever to regain the heavyweight crown after losing it, winning the return match in five rounds.
The pair, both amiable men and later friends after they retired, fought a rubber match in 1961. Johansson, coming in at a career-high 206 pounds, decked Patterson in the first round but was ultimately knocked out in the sixth.
Ingo, as he was known, won four more bouts before retiring at age 31 in 1963, with a record of 26-2, with 17 knockouts.
Within a decade of his retirement, Swedish politicians banned professional boxing due to the dangers associated with the sport. The ban lasted from 1970 to 2007, when it was lifted.
Johansson's silver medal at the Olympics came 30 years later.
He was originally disqualified in the heavyweight final for not giving his best. Johansson always claimed that he backed away in that fight in an attempt to lure his American opponent Ed Sanders into his right-hand counter. The Swede eventually received his medal years later from the International Olympic Committee.
Johannson had a variety of business interests in his native country after retiring and also lived in Florida for a time.
He was inducted in the International Boxing Federation in Canastota, N.Y., in 2002.
Johansson's death leaves Muhammad Ali (67) as the oldest living undisputed heavyweight champion. Ali is younger than former stablemate Jimmy Ellis (68) and Ernie Terrell (69), who each held portions of the heavyweight title in the 1960s but weren't recognized as world champions.
Johansson was married and divorced twice, and is survived by five children. Funeral arrangements were not immediately announced.