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 do n't think Mayweather was that impressive in his last two defences against Marcos Maidana . He made hard work of those fights . But you ca n'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 can not 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 .
MayweatherFloyd Mayweather and Manny Pacquiao face off in Las Vegas on May 2 . Joe Calzaghe believes Floyd Mayweather 's unbeaten record is a burden . Despite that , the Welshman thinks Floyd Mayweather will beat his opponent . READ : Ricky Hatton gives his prediction to Jeff Powell ahead of the fight . READ : MayweatherFloyd Mayweather vs Manny Pacquiao tickets FINALLY go on sale .