Floyd Mayweather knocked out Victor Ortiz in stunning fashion in the fourth round of their welterweight title fight Saturday, but the finish will win probably cemented his reputation as a villain in the eyes of most boxing fans.

Late in the fourth round, Ortiz head-butted Mayweather and was given a warning by referee Joe Cortez. Ortiz apologized to Mayweather, and leaned in to him as if to give him a hug while Cortez seemingly gave a weak signal for the fight to resume. Mayweather used the opening to throw a hard right that knocked Ortiz out. Mayweather was greeted by a cascade of boos.

In an interview in the ring after the fight, Mayweather talked about being booed. "I got hit by a dirty shot. The rule is protect yourself at all time. We're not here to cry and complain about what he did or I did dirty."

Referee Joe Cortez: "Time was in. [Ortiz] needed to keep his guard up. Mayweather did nothing illegal."

--Houston Mitchell

Photo: Floyd Mayweather Jr. delivers the knockout punch against Victor Ortiz in the fourth round of their title fight on Saturday night in Las Vegas. Credit: Eric Jamison / Associated Press

Header Photos: Credit: Julie Jacobson / Associated Press & Al Bello / Getty Images