During his early career, he had a scuffle at a gas station which cost him $100,000 in prize fight money and five months in jail. As a pro, he quickly racked up a 15–1–2 record in his first 18 fights while facing less-than-stellar opposition. His only loss was a decision to undefeated boxer Jimmy Morton. During this time, he fought just three men who had previously won a fight. It caught up with Giardello on January 16, 1950, when he was handed his second defeat by Joe DiMartino, a journeyman with a 6–10 record. After that embarrassment, he began to face better opposition and by 1951, was beating some of the better middleweight boxers on the Philadelphia scene. On June 4, 1954, Los Angeles-based heavyweight boxer
Clarence Henry, who was managed by
Mafiosi Frank "Blinky" Palermo, was arrested in
New York City for
attempting to bribe Oakland middleweight Bobby Jones to throw his June 11
Madison Square Garden match with Giardello. Henry allegedly offered $15,000 to Jones to throw the fight. Once the third-ranked heavyweight contender, Henry was released after posting $2,000 bail and subsequently retired from the ring. Giardello beat Jones in a close decision. Giardello's fight vs.
Billy Graham was the next significant bout. The decision first was awarded to Giardello, then later reversed to a decision in favor of Graham, then reversed again, some time later as a result of litigation, in favor of Giardello. This fight is known in boxing lore as "The reversed reversal." In 1960, Giardello received his first championship opportunity. On April 20, he faced
Gene Fullmer for the
National Boxing Association version of the world middleweight title. He missed out on the title when he and Fullmer fought to a draw over 15 rounds. Giardello lost four of his next six fights, but then came back strong with an 8–1–1 record in his next 10, all of which were over some of the biggest names in the division at that time. One of his wins, a 10-round decision over Henry Hank on January 30, 1962, was chosen as
Ring Magazine's fight of the year. Then, on June 24, 1963, Giardello upset boxing legend
Sugar Ray Robinson, and at the age of 33, was finally named as the No. 1 challenger for the world middleweight title. On December 7, 1963, Giardello faced
Dick Tiger in
Atlantic City for the title and won a controversial decision in 15 rounds. He reigned as world champion for nearly two years, winning four fights during that time. On December 14, 1964, he fought "Hurricane"
Rubin Carter in a title defense. In the first three rounds, Carter stalked Giardello and was the aggressor, as the champion looked to stay away from Carter's left hook. In the 4th round, Carter opened a cut over Giardello's left eye and staggered him with several head shots. By the 13th round, Carter had begun to tire, and Giardello began pounding Carter's head and body, which continued through the 15th and final round. According to Carter, he dominated Giardello the first ten rounds, but Giardello was awarded a unanimous decision, an event dramatized in the 1999 film
The Hurricane. Carter would later revise his claims, admitting he should have fought Giardello more aggressively. In a rematch with Dick Tiger on October 21, 1965, the
Nigerian won a unanimous decision over Giardello in 15 rounds to regain the belt. Giardello was described as "back pedaling for most of the fight." Giardello fought just four more times over the next two years before retiring. ==Professional boxing record==