Joe Calzaghe has insisted that the fire burns as fiercely inside him as ever as he looks to enter boxing's record books when he takes on reality TV star Peter Manfredo.The 35-year-old Welshman will join Larry Holmes and Bernard Hopkins in making 20 successful title defences if he beats Manfredo when he again puts his WBO super-middleweight crown on the line on Saturday night in Cardiff.A crowd of around 35,000 is expected at the Millennium Stadium and, following his emphatic win over Jeff Lacy in March last year, Calzaghe hopes to further enhance his status across both sides of the Atlantic.He said: "I have been through the years of frustration of not being given the big fights and not really getting the credit and respect by a lot of people. Now I am fighting in front of big worldwide audiences and getting that recognition. If you can't get motivated to fight in front of 35,000 people, there is something wrong with you."There is still a lot of fire inside me. My book is not written yet and there is so much I still believe I can achieve. I have given Peter respect by getting into the best shape I have ever been in."Calzaghe, who has held the WBO title since beating Chris Eubank ten years ago, goes into his clash with 26-year-old Manfredo undefeated in his 42 fights to date.But five-times world middleweight champion Sugar Ray Leonard, who has been helping the American fighter, has warned that the underdog could prosper in Cardiff just as he did 20 years ago when he dethroned Marvin Hagler via a split decision at Caesars Palace in Las Vegas.Leonard said: "I hear people asking Calzaghe who's next and they are all totally overlooking Peter Manfredo. They asked the same things to Hagler before our fight."They gave me no shot whatsoever, and I think there is such a parallel it is like deja-vu. I can guarantee Peter will come to fight and he will make it an intriguing contest."© Independent Television News Limited 2007. All rights reserved.