Leon Spinks, who surprised the boxing world by beating Muhammad Ali for the world heavyweight title in 1978, died Friday night at age 67, according to the Firm PR, which represents him.

Spinks had been suffering from prostate and other cancers.

The St. Louis native, who had won a gold medal as a light heavyweight at the 1976 Olympics, was just 13 months and eight fights into his pro boxing career when he stepped into a ring in Las Vegas on Feb. 15, 1978, against Ali.

But Spinks -- a heavy underdog who had never gone beyond 10 rounds --- came right after the champ, who was 36 years old and clearly on the downside of his career.

Spinks, then 24, had enough endurance to survive a 15th-round flurry from Ali -- and provide one of his own in the closing seconds. The split decision went to Spinks, who flashed his famous gap-toothed grin after becoming the only fighter to take a title from Ali in the ring.

But that would turn out to be the highlight of Spinks' career. First, he was stripped of the WBC title for refusing to defend against top contender Ken Norton. Instead, Spinks chose a rematch with Ali, who took back the WBA title in a unanimous decision at the Superdome in New Orleans seven months after their first bout.

The boxing world has lost Leon Spinks . We send our sympathy to Brenda, family and friends. May he Rest In Peace pic.twitter.com/rGnPfbHWAp

— Mauricio Sulaiman (@wbcmoro) February 6, 2021

Spinks would fight just once more for the heavyweight title, a TKO loss to Larry Holmes for the WBC belt in June 1981. He then dropped down to the cruiserweight division, but lost his only title shot to Dwight Muhammad Qawi on a sixth-round TKO in March 1986.

Spinks retired at age 42 after losing a unanimous decision to Fred Houpe in December 1995, and finished his career with an unremarkable record of 26-17-3 (14 KO's).

Spinks, who battled in wrestling and mixed martial arts later in his career, dealt with financial and medical problems later in life. In 2014, he suffered intestinal damage and was hospitalized after swallowing a piece of chicken bone. It led to multiple surgeries. In 2019, he was in and out of the hospital while undergoing treatment for prostate cancer.

Spinks was the brother of Hall of Fame former heavyweight and light heavyweight champion Michael Spinks and the father of former undisputed welterweight world champion Cory Spinks.