Mayweather's Controversial Victory Over Ortiz.

(Reuters) - Floyd Mayweather Jr took the WBC Welterweight title from Victor Ortiz with a controversial fourth-round knockout on Saturday that prompted an angry response from the crowd and raised questions about his conduct in the ring.

Victor Oritz (L), Floyd Mayweather (R)

Aggressive puncher Ortiz had knocked down 12 of his previous 13 opponents and he pinned fellow American Mayweather against the ropes before being penalized by referee Joe Cortez for a head-butt.

After a brief time-out, Ortiz apologized to his opponent in the center of the ring by touching gloves before Mayweather suddenly responded with a left hook and crunching right that dropped Ortiz to the canvas at 2:59.

Boos rang out from the crowd in the MGM Grand Garden Arena but Mayweather, who improved his professional career record to a perfect 42-0 with 26 knockouts, was unrepentant.

"I got hit with a dirty shot, I was protecting myself at all times," the 34-year-old said ringside. "I hit him with a left and then a right hand, and that ended the bout."

Asked to describe what happened as a replay of the final moments was shown on a giant television screen, Mayweather replied: "We touched gloves and we were back to fighting, then I threw the left and right hand and that's all she wrote.

"In the ring, you just have to protect yourself at all times. I was victorious. If he wants a re-match, he can get a re-match."

Mayweather, widely regarded as the best defensive fighter of his generation, then showered his interviewer with abuse and said he had never been given "a fair shake."

Ortiz, who took the WBC welterweight title from Andre Berto in April with an unanimous points victory, conceded the head-butt had been unfortunate but was eager to get a re-match with Mayweather.

Floyd Mayweather's Post Fight Interview.

EDITOR'S RESPONSE: Personally i don't see anything "controversial" about how Mayweather won the fight. Ortiz head-butted him several times through out the course of the match but somehow people automatically over  look that fact. You are supposed to protect yourself AT ALL TIMES!! That's a fundamental rule to keep in mind in the sport of boxing.  In addition, the ref clearly signaled for the round to be under way, but Ortiz was too caught up in apologizing, which would not have been necessary if he had not butted Mayweather in the first place.

Author: Mark Lamport-Stokes (Reuters)