text: Unbeaten Floyd Mayweather faces more pressure than Manny Pacquiao when the pair meet in Las Vegas on May 2 but he will still be victorious, says Joe Calzaghe. It is being billed as The Fight of the Century, and is worth at least $180million and $120m to Mayweather and Pacquiao respectively, but former undefeated world super-middleweight and light-heavyweight boxing champion Calzaghe is confident he can predict the outcome. 'There will be a lot more pressure on Mayweather than there will be on Pacquiao,' he told BBC Sport. 'Pacquiao has been beaten so he'll be more relaxed than Mayweather. The "zero" is a massive burden. Floyd Mayweather works out with his uncle Roger at the Mayweather Boxing Club ahead of the fight . Mayweather holds an impressive undefeated professional boxing record going into the fight on May 2 . Mayweather faces Manny Pacquiao in a bout in Las Vegas that has been billed 'The Fight of the Century' 'I don't think Mayweather was that impressive in his last two defences against Marcos Maidana. He made hard work of those fights. But you can't overlook a guy that's never lost. Mayweather is a fantastic fighter who always finds a way to win so he will be ready for this fight.' Mayweather has an impressive record, winning all of his previous 47 professional career fights, 26 by knockout. His opponent Pacquiao goes into the bout having lost five times in his career, with 57 wins and two draws overall, but Welshman Calzaghe warns Mayweather cannot underestimate his challenger. The Welshman, who is now 43,  retired with an undefeated record of 46 wins and zero defeats. 'Pacquiao can fight and there's always one great fight left in somebody,' Calzaghe added. 'But I think the win will go to Mayweather.' Tickets for the much-anticipated fight finally go on sale on Thursday night after months of speculation, and are expected to fetch between $1,500 (£1,000) and $7,500 (£5,000) apiece. Calzaghe takes part in a training session alongside his coach and friend Freddie Roach in Los Angeles . Pacquaio is watched by a crowd as he trains in Los Angeles, but Joe Calzaghe has backed his opponent . Calzaghe, who himself retired undefeated, believes Mayweather will overcome the challenge of Pacquiao .
target: Floyd Mayweather and Manny Pacquiao face off in Las Vegas on May 2 .
  Joe Calzaghe believes Mayweather's unbeaten record is a burden .
  Despite that, the Welshman thinks Mayweather will beat his opponent .
  READ: Ricky Hatton gives his prediction to Jeff Powell ahead of the fight .
  READ: Floyd Mayweather vs Manny Pacquiao tickets FINALLY go on sale .