Former Heavyweight Boxer Ken Norton Sr. Passes Away at 70

Ken Norton Sr., an International Boxing Hall of Famer who is recognized by pundits as one of the greatest heavyweights in the sport's history, died Wednesday after a long battle with congestive heart failure.

He was 70 years old.

Norton, whose professional boxing career spanned three decades, died at an Arizona hospital where he had been undergoing rehabilitation due to complications stemming from a stroke, according to the Los Angeles Times' Claire Noland. Norton had previously overcome two strokes, a heart attack, quadruple bypass surgery and prostate cancer.

Upon hearing of Norton's passing, many in the sports community reached out to offer their condolences:

The former heavyweight champ is perhaps best known by boxing fans for his trilogy of fights against Muhammad Ali in 1973 and 1976. In the first bout between the two men, held at the San Diego Sports Arena, Norton shocked the world by defeating Ali in a split-decision and breaking his jaw in the process.   

Ali would get revenge with controversial victories in their next two fights—one later in 1973 and the other in 1976—but Norton's victory over Ali in their first fight made him a star. He parlayed that notoriety into a fight against George Foreman in 1974, and a title win over Jerry Quarry in 1975 when Ali had vacated the strap. 

Though Norton would lose the belt back to Ali in 1976, he would be awarded the WBC championship a year later. Larry Holmes defeated a declining Norton in 1978, ending a championship run that had lasted parts of five years. 

Inside the sport of boxing, Norton is well-known for popularizing the cross-armed defense. Rarely seen before Norton employed the tactic to success early in his career—most notably against Ali—multiple other heavyweights began adopting it.

Norton, though, had perfected the craft. Where other fighters who used cross-armed protection often struggled with counterpunching, Norton's hands were quick enough that he rarely had that problem. He finished with a career record of 42-7-1 with 33 knockout victories. His last fight came in 1981, when he was knocked out by Gerry Cooney at Madison Square Garden. 

After Norton's boxing career, he worked in the entertainment industry as an actor and commentator. He appeared in television shows like The A-Team and Knight Rider during the 1980s.

Norton is survived by his two sons, one of which is former NFL linebacker Ken Norton Jr., who won three Super Bowls over his 13-year career with the Dallas Cowboys and San Francisco 49ers. Norton Jr. is currently the linebackers coach for the Seattle Seahawks.