The comeback of Iran Barkley began five years ago at a nightclub in the South Bronx, a short jog from the gang-infested neighborhood where he first learned to use his fists. It was a skill that would eventually help him earn three world boxing titles and what he estimated to be more than $5 million.

Seated across the bar that February evening in 2010 was Pamela Graham, a widow from Brooklyn with five children whose interests did not include sports.

“A friend of mine said, ‘Hey, the champ is staring at you,’” Ms. Graham, 47, said of the incident. “I was like, ‘The champ? The champ of what? Who’s the champ?’”

She looked up and made brief eye contact with Mr. Barkley.

“I saw this handsome guy staring at me, but he wasn’t smiling,” Ms. Graham said. “He seemed very, very angry.”