Mayweather defeats Victor Ortiz in controversial fourth-round knockout

Mayweather improved to 42-0 and claimed the WBC world welterweight title as he blasted Ortiz (29-3-2) to defeat amid sensational scenes.

The controversial finish came after Ortiz was deducted a point late in the round by referee Joe Cortez for an intentional headbutt. Then Ortiz, clearly full of regret, cuddled Floyd and apologised.

As the two fighters then broke, Mayweather unloaded with a left hook and a right that sent Ortiz crashing to the canvas. TV replays appeared to show that neither Ortiz or Cortez were looking at Floyd when he unloladed.

The controversial ending may well take some of the gloss off what had up to that point been a virtuoso performance from 'Money'.

Despite a 16-month absence from the ring he was in the groove right from the opening bell, and could hardly miss with that trademark right-hand counter.

Ortiz tried to get inside and throw punches in bunches, but Floyd merely smiled through his gumshield time and again before countering and making good his escape.

By round four it was a boxing lesson from Mayweather Jr, with Ortiz quite simply outclassed. And it appeared that frustration got the better of Victor as he butted Mayweather with Floyd on the ropes.

Then, within seconds it was over, with the MGM Grand erupting into chaos as Mayweather delivered the knockout blow.