[1] He represented Jamaica at the 1984 Olympics, and won a bronze medal in the heavyweight division at the 1983 Pan American Games.

During his professional career, he fought world champions Mike Tyson, Evander Holyfield, George Foreman, Oleg Maskaev, and Michael Moorer.

He was beaten by Sweden's Håkan Brock in the quarter final of the heavyweight competition, losing by a 5–0 decision.

Stewart reeled off 24 consecutive wins, all by KO, prior to his defeat to Evander Holyfield, to whom he lost twice.

[3] Stewart is probably best known for being blown out by Mike Tyson in the first round in 1990 at Trump Plaza in Atlantic City.,[4][5] and lost to other notable heavyweights of his era, including Michael Moorer, George Foreman, and Oleg Maskaev.