Judges awarded the 12-round victory in the all-American slugfest to Garcia by three identical scores of 116-112.

Garcia rose to 32-0 in only his second bout in the 147-pound weight class since moving up after winning the WBC and World Boxing Association titles at junior welterweight.

"It was a great fight," Garcia said. "I felt I won the fight clearly and the judges said the same thing."

Guerrero, 32, pressed the attack early but Garcia, 27, answered with hammering exchanges, rocking his rival particularly in the sixth and ninth rounds.

An intense exchange of blows in the final round had the crowd standing and cheering. The fighters fired rapid flurries of punches then hugged in the center of the ring after the final bell.

Southpaw Guerrero fell to 33-4 with one drawn. It marked his third world title loss in the division, having fallen to Mayweather in 2013 and unbeaten Keith Thurman, the reigning WBA champion, last March.

Garcia faces a mandatory defense against England's Amir Khan, who was stopped in the fourth round by Garcia in 2012, but other foes are possible as well.

"I want to fight the best," he said. "Danny Garcia never ducked anybody."

Thurman, who provided television commentary on the fight, defends his WBA crown in March against former world champion Shawn Porter and longingly eyed Garcia's title.

"That green belt looks pretty good," Thurman said. "I would like to see it around my waist later this year."

Mayweather, who retired last September after a 49-0 career, watched from ringside and rejected any notion of a return to the sport anytime soon.

"As of right now, I don't have the urge to fight," Mayweather said, avoiding a choice on who he sees as his successor by saying, "There's a lot of great talent out there."

Filling the void as the welterweight king after Mayweather's retirement could take some time as rival champions have differing agendas.

Britain's unbeaten Kell Brook defends his IBF crown in March against Canadian Kevin Bizier while American Tim Bradley defends his World Boxing Organization crown in April against Filipino icon Manny Pacquiao.