Ishe Smith seized the International Boxing Federation junior middleweight world title on Saturday with a 12-round split decision over hometown hero Cornelius Bundrage.
In a fight marked by repeated holding and shoving, Smith outworked the 39-year-old champion in the late rounds to earn scores of 116-111 from two judges, while the third saw it 114-113 for Bundrage.
It was enough to make Smith the first fighter born in the boxing haven of Las Vegas to win a world boxing title.
The 34-year-old promoted by unbeaten welterweight Floyd Mayweather improved to 25-5 with 11 wins inside the distance.
It was an emotional win for a fighter who said he once contemplated suicide after his ring career went off the rails and his marriage failed.
He wept as he thanked Mayweather in the ring after the bout.
"It means everything," said Smith, who said that five years ago he was so low that he was ready to kill himself but did not want to leave his children without a father.
"I didn't think I'd be here man," he added, struggling for composure.
Bundrage was the aggressor for most of the bout, using his jab to neutralize Smith's dangerous counter-punching ability.
Smith did catch the champion with a solid combination late in the third round, but was mainly on the defensive until the ninth, when he finally unleashed a flurry that rocked Bundrage.
Bundrage, fell to 32-5, with 19 knockouts, unable to benefit from the vocal support of the hometown fans in his first fight in Detroit since 2005.
"Ishe just fought a good fight. He won the fight fair and square," Bundrage said. "I didn't follow instructions. He won it. He won the fight. Congratulations to him."