Los Angeles - Manny Pacquiao trainer Freddie Roach drew first blood in the war of words with Floyd Mayweather on Wednesday as the countdown to the biggest boxing bout in history got under way.
In remarks to a packed press conference attended by an estimated 600 journalists, Roach said Pacquiao's eagerly awaited May 2 title fight with Mayweather in Las Vegas represented the biggest challenge of his celebrated career as one of boxing's most respected trainers.
But Roach did not mince his words as he wrapped up his comments with a blunt assessment of Pacquiao's task.
"We're fighting the best fighter in the world - and we're going to kick his ass," Roach said to cheers from sections of the audience, with Mayweather sitting just a few feet away on the stage in Los Angeles.
"I love challenges and this is the biggest challenge of my life," Roach said. "It's finally here. I've been looking forward to this fight for years.
"It's the toughest fight of our life. I'm going to get my fighter as ready as possible."
Pacquiao's bout with the unbeaten Mayweather represents the climax to years of will-they won't-they speculation surrounding the possibility of a showdown between the two rivals, widely regarded as the finest fighters of their generation.
The fight finally became a reality earlier this year when Pacquiao and Mayweather met informally at an NBA basketball game and expressed a mutual desire to make the contest finally happen.
"It's been a long road, but we're here now," Mayweather said. "It's all about the best fighting the best, and Pacquiao is one of the best."
May's fight is expected to be the highest-grossing bout in history, with Mayweather reportedly set to collect a staggering $120 million while Pacquiao will pocket a cool $80 million.