His biggest breakthrough, however, came in 1989, when Sylvester Stallone was a spectator at one of Morrison's bouts and realised that Morrison would be ideal for Rocky V. Stallone arranged for Morrison to have a script reading, and was cast as Tommy Gunn in the movie. While Morrison did win two fights in 1990, it was when Rocky V was released in December of that year that he gained mainstream popularity.
In 1991, Morrison, already the receiver of much television exposure, won four fights, against opponents the calibre of former Larry Holmes world title challenger and Tyson opponent James Quick Tillis, and former world champion Pinklon Thomas. He was then given a crack at becoming world Heavyweight champion by WBO champ Ray Mercer in a Pay Per View card held on October 18 1991. Morrison lost what turned out to be a highlight film knockout in round five.
Morrison had six wins in 1992, including one over former Riddick Bowe opponent Art Tucker, and one over future world title challenger Joe Hipp, who would later become the first Native American to challenge for the world Heavyweight title. After two wins in 1993, including one over two-time former world title challenger Carl Williams, Morrison found himself fighting for the world championship again, this time against Foreman, On June 7. Morrison surprised many critics by outpointing Foreman over 12 rounds, winning the world title. Almost immediately, talks of a fight with WBC world champion Lennox Lewis began, although it would not have been a unification bout, because the WBC has always refused to have recognised the WBO.
Talks of a Morrison-Lewis fight, however, momentarily came to a stop because Morrison was himself upset in his first defense by virtually unknown Michael Bentt, being knocked out in round one in front of a live HBO Boxing audience.
He recovered by winning three bouts in a row in 1994, but then, he drew in his last fight of the year, against another virtual unknown, Ross Puritty.
He won three fights in 1995 before meeting Razor Ruddock for the IBC Heavyweight Championship. This fight was named fight of the year by various magazines, as Morrison dropped Ruddock several times, but had to climb off the canvas in round one himself before scoring a sixth round knockout win.
The fight with Lewis, who had also lost his world championship, finally came off after the fight against Ruddock. Lewis stopped Morrison in six rounds.
A few days before his next fight, to be shown on Showtime, Morrison had a mandatory HIV test performed by the Nevada state athletic commission. It was revealed during Showtime's telecast of the boxing undercard, that Morrison was on a flight home to Oklahoma City, following the revelation that the HIV test proved positive, automatically retiring him from boxing as a competitor.
Later in 1996, Morrison announced that he wished to make a comeback with one more bout, the proceeds of which would go to benefit his newly created KnockOut Aids Foundation. Morrison won what would turn out to be his final fight, a first round knockout of Marcus Rhode in Tokyo. Morrison finished his boxing career with a record of 46 wins, 3 losses, 1 draw, with 40 of his wins by knockout.
- Wicked left hook
Best remembered for his role as Tommy Gunn in Rocky V
Announced his retirement in early 1996 after being diagnosed HIV positive right before a scheduled bout with Arthur Weathers.
Years after his first retirement, Morrison admitted he'd used steroids during his career
All Divisions (Pro)
Major World Titles
TKO 6 Razor Ruddock - 1995
UD 12 George Foreman - 1993
TKO 8 Carl Williams - 1993
TKO 9 Joe Hipp - 1992
TKO 5 Yuri Vaulin - 1991
TKO 1 Pinklon Thomas 1991
TKO 1 James Tillis - 1991
TKO 6 Lennox Lewis - 1995
TKO 1 Michael Bentt - 1993
TKO 5 Ray Mercer - 1991