J.D. Smith, a two-time Pro Bowl running back who retired as the 49ers’ second-leading career rusher and is still sixth on the list, died April 1 at his home in Oakland. He was 83.

Mr. Smith, a native of Greenville, S.C., was nicknamed “Cinderella Man” for his unlikely path to the NFL.

“If they had ESPN back then, he would have made a really good story,” said Christian Duncan, Mr. Smith’s grandson.

A 15th-round draft pick by the Bears out of North Carolina AT&T State, Mr. Smith served a year in the U.S. Army before beginning his career with Chicago in 1956. The Bears used him sparingly and eventually released him. He then signed with San Francisco.

He played defense in 1957, but moved in 1958 to offense. The move paid off when, in 1959, the 6-foot-1, 205-pounder earned his first Pro Bowl selection by rushing for 1,036 yards (second best in the league to Jim Brown’s 1,329 for Cleveland) and a team-record-tying 10 TDs.

He also won the team’s Len Eshmont Award for inspirational and courageous play.

“He was very humble, I never heard about football from him,” Duncan said. “I think I learned about it by going with him to alumni games. And he had a basement full of old NFL memorabilia and one of the things is the Len Eshmont Award. It was then that I realized that granddad was pretty serious about football.”

Mr. Smith’s other Pro Bowl season was 1962, when he gained 907 yards and scored six times.

Mr. Smith’s last season with the 49ers was 1964. He played two seasons with the Cowboys before retiring after the 1966 season.

Fifty years later, he’s still fifth in 49ers history for rushing TDs (37, tied with Steve Young) and 100-yard games (12, tied with Hugh McElhenny) and is sixth in yards (4,370) and carries (1,007).

Mr. Smith is survived by his daughter, Patricia, sons Lonnie and David, three grandchildren and three great-grandchildren. The family will hold a private memorial at Kezar Stadium.

The family has asked that donations be made to the Foundation for the National Institutes of Health Sports and Health Research program.

Michael Lerseth is a San Francisco Chronicle staff writer. E-mail: mlerseth@sfchronicle.com