WASHINGTON • Andre Berto is blocking out the hype for his welterweight world title bout against Floyd Mayweather Jr and believes the pound-for-pound king is no longer the fighter he was.

Berto, 31, may have lost three of his last six fights and may be a massive underdog against Mayweather, but the two-time former champion said on Tuesday that he is in the best shape of his life, as he attempts to become the first man to beat his fellow American.

Mayweather has said that he intends to hang up his gloves after the Sept 12 showdown in Las Vegas, and he infuriated boxing fans in hand-picking Berto when there are more attractive - but more dangerous - fighters in the field.

He will match the 49-0 win-loss record of Rocky Marciano if, as expected, he defeats Berto.

But Berto (30-3, 23 KOs) is laughing off all the flak, talk of records and his opponent's propensity for showing off his staggering wealth to the world.

"I don't get caught up in all the hoop-la," he told reporters in a conference call.

"I don't want to get caught up and caught off guard... I'm on a mission."

Berto says he has the speed, power and hunger to spring a major surprise at the MGM Grand and believes Mayweather (48-0, 26 KOs) is starting to feel the heat at age 38.

Experts say Mayweather, a master of defence, has become slightly easier to hit in recent fights.

However, he still had more than enough to put Filipino boxing superstar Manny Pacquiao to the sword in his last bout.

Berto agrees he sees some chinks in Mayweather's armour: "He's definitely showing some slippage throughout the years, in the last couple of fights.

"But you can be as sharp as you want, but it only takes one slip for somebody to capitalise on it."

AGENCE FRANCE-PRESSE