The 67-year-old died Saturday from cancer, his ex-wife says.
Kelly was offered his first acting role in the action-packed film Melinda while he still worked as a martial arts instructor in Los Angeles. His second role, and perhaps his most memorable, was alongside Bruce Lee in the 1973 cult-classic Enter the Dragon.
His career peaked during the ‘70s when he took on a lineup of roles including Three the Hard Way and the lead role in Black Belt Jones.
In later years, Kelly stopped his martial arts work and took up tennis professionally. He became a ranked player on the U.S. Tennis Association senior circuit.
In 2004, Kelly made an appearance alongside LeBron James in a Nike commercial that alluded to the Bruce Lee film Game of Death.
In an interview with Salon in 2010, Kelly said he started studying martial arts in 1964 in Kentucky and wanted to become an actor after winning karate tournaments.
Fans of Kelly will remember him for his punchy on-camera persona and snappy catchphrases like, “I’ll be too busy lookin’ good” and “you come right out of a comic book.”