September 12 of 1928 was the date of Carnera's first professional fight, against Leon Sebilo, in Paris. Carnera won by knockout in round two. He won his first six bouts, then lost to Franz Diener by disqualification in round one at Leipzig. Then, he won seven more bouts in a row before meeting Young Stribling. He and Stribling exchanged disqualification wins, Carnera winning the first in four rounds, and Stribling winning the rematch in round seven. In Carnera's next bout, he avenged his defeat to Diener, with a knockout in round six.
In 1930, he moved to the United States, where he toured extensively, winning his first seventeen bouts there by knockout. One of the boxers he beat during that streak was Jack McAuliffe. The one rival who broke the streak was George Godfrey, beaten by disqualification in five in Philadelphia. Carnera lost a decision to Jim Maloney in Boston to finish 1930.
In 1931, he went 7-1. He beat Maloney and King Levinsky, but his sole loss that year was to future world Heavyweight champion Jack Sharkey.
In 1932, he went 23-2, with 17 knockouts, but mostly against obscure opposition.
1933 was one of the most important years in Carnera's life: On February 10, he knocked out Ernie Schaaf in thirteen rounds in New York. Schaaf passed away two days later and Carnera had to go through what most boxers wish they did not have to: the death of an opponent. For his next fight, Carnera faced the by then world Heavyweight champion Sharkey, with the crown on the line. The date of the championship date was June 29, at the Madison Square Garden's bowl at Long Island. Carnera became world champion by knocking out Sharkey in round six.
He retained the title against Paulino Uzcudun (who was attempting to become the first Hispanic world Heavyweight champion) and Tommy Loughran, both by decision in 15 rounds, but in his next fight, against Max Baer, he was dropped 12 times en route to an 11 round knockout defeat.
After that, he won his next four fights, three of them as part of a South American tour that took him to Brazil, Argentina and Uruguay, as well as boxing two exhibitions in the southern American continent. But then , in his next fight of importance, on June 25, 1935, he was knocked out in six rounds by a future world Heavyweight champion named Joe Louis.
For the next three years, he had a rather ordinary record, winning four bouts and losing four. But in 1938, Carnera, a diabetic, had to have a kidney removed, for which he had forced retirement until 1944.
Carnera's manager, a gangster named Owney Madden, stole much of Carnera's money and left him almost broke. Because of Madden's connection to the underworld, it has always been speculated across the boxing world that most of Carnera's fights were fixed. The book East Side, West Side: Tales of New York Sporting Life 1910-1960 took the rumors a step further, stating that Most of the Italian giant's opponents were pushovers, paid to take a dive or too frightened to stand up for three minutes in a row. Jack Sharkey himself had to deny rumors about him taking a dive in his world championship fight with Carnera. swearing that he didn't.
Carnera in his time off boxing went to Hollywood and tried his fortune there, and he did well in the city of the stars, participating in a number of movies, his starring job in A Kid For Two Farthings being critically acclaimed. In 1945, he attempted a comeback to boxing, and he won two fights in a row. But after losing to Luigi Mussina three times in a row, he quit boxing for good. In 1946, he became a professional wrestler. Supposedly, he and Baer engaged in a wrestling match, no evidence of that happening was actually ever found.
In 1953, Carnera married Guiseppina Kovacic, and they immediately became American citizens. They settled in Los Angeles, where Carnera opened a restaurant and a liquor store. They had two kids, of which one became a medical doctor.
In 1954, Federico Fellini's La Strada, featuring Anthony Quinn as a boxer, was released. Many fans thought the movie's story had some resemblance to Carnera's life. But in 1956, when Budd Schulberg wrote his novel, The Harder They Fall, a story about a boxer whose fights are fixed, and a movie with the same name and based on the novel was released by Columbia Pictures, Carnera sued the movie company, but he lost. In 1957, he beat King Kong, to claim wrestling's world Heavyweight championship and become the first, and so far only, man in history to win both boxing's and wrestling's world Heavyweight championships.
Carnera died in 1967, of a combination of diabetes complications and liver disease.
Even after his death, rumors that put the results of his bouts in doubt kept roaming around the boxing world. The legitimacy of Carnera's fight's results might be one of boxing's greatest incognitos ever. Well into the 2000s, this is a subject many critics, historians, analysts and fans as well talk about. It shall be said, however, that Carnera himself apparently did not know of the supposed fixings.
Carnera's record was of 87 wins, 14 losses and 1 no-decision, his 69 wins by knockout making him a member of the exclusive club of boxers that won 50 or more bouts by knockout.