Stiverne commenced his amateur career in boxing at age 19. He won two successive bronze medals, one each in 2003 and 2004, and a silver medal in 2005. He defeated David Price by knockout and Robert Helenius by points, in international competitions.
The amateur career of Stiverne includes an impressive 49 wins against 10 losses. Regarding his absence from the ‘Olympics,’ Stiverne said that he was robbed during the semi-finals of a qualifying tournament in Mexico, where he faced a Mexican fighter. According to him, although he knocked down his opponent, Mexican–American George Garcia, thrice, the final decision was given in favor of the latter.
Stiverne turned professional under American boxing promoter Don King and made his professional debut on July 29, 2005, in a match where he beat Roy Matthews by technical knockout (TKO) at ‘The Plex’ in North Charleston, South Carolina, US. He then knocked out his next 11 opponents, applying his trademark left hook, before facing his first defeat on July 7, 2007, in a match against Demetrice King at ‘The Arena at Harbor Yard’ (presently the ‘Webster Bank Arena’) in Bridgeport, Connecticut, US.
In the ensuing years, Stiverne displayed an impressive form, winning a string of matches against different opponents, such as Edward Gutierrez, Lyle McDowell, and Robert Hawkins. His winning spree continued except a draw with Charles Davis on April 29, 2009, before he faced Kertson Manswell on February 29, 2011, in a match at the ‘Silverdome’ in Pontiac, Michigan, US. The match resulted in Stiverne winning the vacant ‘WBA Fedelatin,’ the ‘WBC International,’ and the ‘WBC USNBC’ heavyweight titles.
On June 25, 2011, he fought against Ray Austin and won the vacant ‘WBC Silver’ heavyweight title by a 10-round TKO at the ‘Family Arena,’ St. Charles, Missouri, US. This made him the mandatory challenger for the ‘WBC’ heavyweight title, which at that time was held by Vitali Klitschko.
Stiverne then fought and won matches against Willie Herring and Chris Arreola. When Klitschko vacated the ‘WBC’ heavyweight championship title in December 2013, Stiverne signed to face Arreola in a match for the vacant title. The match was held at the ‘Galen Center’ in Los Angeles, California, US, on May 10, 2014. Stiverne beat Arreola after a sixth-round knockout to win the title. This made Stiverne the first Haitian-born boxer to earn a world heavyweight championship title and also the first to win the ‘WBC’ world heavyweight championship out of the province of Quebec.
Noted Haitian personalities took to social media to congratulate Stiverne on his ‘WBC’ world heavyweight championship title win. Such personalities included former singer and ex-president of Haiti, Michel Martelly; professional boxer and two-time welterweight world champion Andre Berto; American football wide receiver Pierre Garçon; and three-time ‘Grammy award’-winner Haitian rapper, musician, and actor Wyclef Jean.
Stiverne lost the ‘WBC’ world heavyweight championship title by a wide unanimous decision, in a match against American professional boxer Deontay Wilder. The match was held at the ‘MGM Grand Garden Arena’ in Paradise, Nevada, US, on January 17, 2015. Stiverne was hospitalized after the match, following which he was diagnosed with rhabdomyolysis.
The ‘WBC’ ordered a match between Stiverne and mandatory challenger Povetkin for the interim ‘WBC’ heavyweight title in 2016, the winner of which was supposed to challenge the then-champion Wilder for the full version of the title. Wilder, who was out of action at that time due to surgeries on his hand and biceps, gave his consent to face the match’s winner.
On November 11, 2016, the ‘Voluntary Anti-Doping Association’ (VADA) informed the ‘WBC’ that Stiverne had tested positive for the banned substance methylhexaneamine. The ace boxer cooperated with the investigative process and claimed that he had consumed the post-workout supplement ‘Superharm’ to facilitate urination, without being aware that it contained methylhexaneamine.
However, as per the rules of ‘VADA,’ anything that goes into the bodies of athletes is their responsibility. Considering that Stiverne had never tested positive in the past, the ‘WBC’ fined him $75,000 and gave a green signal to the fight. No evidence was found indicating that Stiverne had intentionally consumed the banned substance to enhance his performance. The organization, however, withdrew its sanction of the fight merely 20 hours before its scheduled time on December 17, 2016, mentioning that Povetkin had failed a drug test for ostarine. Stiverne refused to participate in the bout. He presently fights in Las Vegas.
He had a re-match with Wilder for the ‘WBC’ world heavyweight title, on November 4, 2017, at the ‘Barclays Center’ in New York City, New York, US. Stiverne had promised his wife and children that he would beat Wilder and regain the title. His family was present at the venue to watch the fight. Stiverne, however, had an embarrassing loss in the match, after being knocked unconscious by Wilder in the first round. Nevertheless, at that time, he became the only opponent to fight 12 rounds with Wilder.