WBA/WBC welterweight champion Floyd Mayweather has carried his unbeaten streak to 47 straight fights with a unanimous decision victory over Argentine Marcos Maidana in their 12-round rematch.

Mayweather, who hasn't lost a fight since the 1996 Olympics, improved to 47-0 as two judges scored it 116-111 and the third had it 115-112 for the champion, who was a heavy favourite coming into Saturday's bout after winning the first fight by a majority decision in May.

The fight was held up momentarily in the eighth round when Mayweather complained that Maidana bit him on the wrist while the two were tied up. Maidana was penalised for tripping Mayweather in the 10th round.

"I prepared myself very well and thought I won the fight but if the referee prefers to give the fight to fighters who run, I can't do anything about that. I was the aggressor throughout. I kept my game plan but Floyd was holding and pushing and the referee only punished me. I did not bite him in the eighth round. Maybe they think I'm a dog. I never bit him. He had his glove right on my mouth but I did not bite him," Maidana said.