Best known for his left hook and formidable punching power, Morrison won the WBO heavyweight title in 1993 with a unanimous decision victory over George Foreman.

Morrison made a brief comeback to boxing from 2007 to 2008 when the Nevada commission lifted the indefinite worldwide suspension in July 2006,[1] and briefly dabbled in the world of MMA.

As a mixed martial artist, he scored a notable first-round knockout win over Wyoming state heavyweight champion Corey Williams in 2009, which ultimately became the last fight Morrison ever had in combat sports before his final retirement due to his declining health that began in 2011.

On September 1, 2013, Morrison died at the age of 44 from sepsis, septic shock, multi-system organ failure and, ultimately, cardiac arrest.

[13] Morrison started his professional boxing career on November 10, 1988,[11] with a first-round knockout of William Muhammad in New York City.

[11] From December 8, 1989, until June 8, 1990, Morrison did not compete in a boxing match, due both to injuries and his involvement in Rocky V. In 1991, Morrison won four bouts, including notable victories against opponents James Tillis, the first man to take Mike Tyson the distance, and former WBC heavyweight champion Pinklon Thomas.

Morrison was then given an opportunity to face fellow undefeated fighter Ray Mercer, the WBO title holder in a Pay Per View card held on October 18, 1991.

[11] He had six wins in 1992, including fights with Art Tucker and Joe Hipp, who later became the first Native American to challenge for the world heavyweight title.

Though the bout was promoted as a match between two of boxing's hardest punchers, neither fighter scored a knockdown nor had their opponent in any real danger.

[22] Though Tomashek gave a good account of himself, reeling off a combination en route to winning the first round on the judges cards, Morrison fought conservatively but dropped his opponent with a multi-punch combination, and the fight was stopped by Tomashek's corner after only four rounds due to him walking to the wrong corner after his brutal punishment by Morrison.

[22] Almost immediately, talks of a fight with WBC champion Lennox Lewis began for reestablishing him as one of the top heavyweight contenders.

[25] Morrison recovered by winning three bouts in a row in 1994, but his last fight of the year, against Ross Puritty, ended with a draw,[26] before he landed a WBO heavyweight title fight against Herbie Hide on the infamous "High Noon in Hong Kong" card, but the event was cancelled at the last minute due to financial issues.

[36] At another news conference on September 19, 1996, in Tulsa, Oklahoma, Morrison announced he wished to fight "one last time" when he could find an opponent, the proceeds of which would benefit his KnockOut AIDS Foundation.

[42][43][44] In February 2008, Morrison was cleared to fight a young and undefeated fighter, Matt Weishaar, 3-0-2 (1 KO), in Leon, Mexico on the undercard of Marco Antonio Rubio vs. Jose Luis Zertuche.

[45] Morrison's age and ring rust were very prominent in the bout, as he nearly stumbled over in round 2, but defended well and retained sharp powerful punches that shook his junior opponent.

Weisharr took the first round on the cards with his jab keeping Tommy off the attack, but Morrison defeated Weisharr by third round TKO, after Weishaar was beginning to be overwhelmed by Morrison's powerful punches and accurately placed blows to the head beginning in the third, leading to the ref waiving off the fight after a hard left hook and right cross.

[49] Due to a paper work issue, not arriving before the date of the fight, Morrison was pulled from the event card.

[50][51] In January 2011, the RACJ, the boxing commission for the province of Quebec, required that Morrison take a supervised HIV test in advance of a scheduled 2011 fight against Erik Barrak (3-0).

He did not need a license to fight as the location was outside the Arizona state jurisdiction, and Stover agreed to the match when it was shown to him that his opponent was allegedly HIV negative.

[55][60] Morrison fought a bout against professional Corey "WizKid" Williams as the main event of the Ultimate Explosion 12: The Last Stand MMA[61] and Boxing fight card on January 31, 2009[62][63] for the Wyoming state heavyweight title.

[65] In 2009, Morrison stated in an interview on MMANews.com that his debut in 2007 was more or less just a favor to his friend, who happened to be the promoter for the event, thus why his MMA career was short lived.

He voiced respect for the sport and those that participated in it, but he decided to stick with boxing as it was what he knew best, stating he never did or ever intended to make a full transition despite popular belief.

[67] The Nevada commission's medical advisory board reviewed Morrison's 1996 test results and concluded they were "ironclad and unequivocal.

[72] In October 1996, Morrison pleaded guilty to transporting a loaded firearm in Jay, Oklahoma; he received a 6-month suspended sentence and a $100 fine.

[73] In 1997, an Oklahoma jury convicted him of DUI in an accident that left three people injured; the court ordered Morrison to spend time in treatment.

[75] On April 3, 2002, he was sentenced to another year in prison after violating parole in Tulsa, Oklahoma, but was given credit for time previously served.

[80] The World Boxing Organization said people would remember Morrison best for his dangerous punching power and especially his left hook.

[81] Two-time heavyweight champion Pinklon Thomas said Morrison hit like a baseball bat and rated him ahead of Mike Tyson as the hardest puncher he had faced.