Did Mayweather do wrong?

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

After a brief time-out, Ortiz apologised to his opponent in the centre 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.

There is nothing in the rules that says Mayweather was not within his rights to "sucker punch" Ortiz but was it an act of terrible sportsmanship? Or a clever piece of opportunism? Leave your thoughts at the bottom of the article.

Here is what some of the big names in the boxing world said about the incident.

Floyd Mayweather: "I got hit with a dirty shot, I was protecting myself at all times. I hit him with a left and then a right hand, and that ended the bout. 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.

Victor Ortiz: "I was called to break by the referee and I obeyed exactly as I was told. And then, boom, he blindsided me. The ref said something. I looked up and he just caught me. I was like: 'Wow', and I woke up after. It happens. It's part of the game."

Joe Cortez: "I had already ordered them to continue fighting and the clock was running, but Ortiz wanted to apologise again and he was off guard. Mayweather, who is more experienced, he took advantage, but did nothing illegal. Nowhere is there a rule that says the boxer has to apologise and hug the other fighter and do it at least two or three times. If you get ordered to fight and the clock is running, you have to fight. Ortiz's inexperience cost him the fight."

Oscar De Lay Hoya: "Ortiz took it to the street and Mayweather finished it in the street. It was bad sportsmanship by Mayweather. Ortiz was just warming up, a young lion does not deserve to go out like that and I will fight for Ortiz to have a rematch."

Lennox Lewis: "After the first punch Ortiz knew that Floyd Mayweather was back to business...yet he looked to the ref instead of covering up. Ortiz made two critical mistakes in last round. The head-butt and after the ref said to fight, to not protect himself at all times."

Manny Pacquiao (according to his Canadian adviser Michael Konc who he watched the fight with): "It was, to say the least, unsportsmanlike but Mayweather should still not be faulted for what happened. Manny thinks it was the young Ortiz’s immaturity and lack of experience that did him in but a boxer who has slightly better self respect and is proud to win "cleanly" would not have done that."

Paulie Malignaggi: "Victor's the one who turned it into a street fight with (head) butts. You can't take it up there and then expect the other guy to take it back down. Besides, you protect yourself at all times."