Martin Murray is planning to retire if he loses to Billy Joe Saunders but believes he will defeat his fellow Briton to finally fulfil his dream of becoming a world champion.
The pair are set to clash at London's O2 Arena on April 14 as Saunders makes the fourth defence of his WBO middleweight belt.
Murray's previous world title fights have been a draw against Felix Sturm in Germany and losses to Sergio Martinez in Argentina, Gennady Golovkin in Monaco and - at super-middleweight - Arthur Abraham, also in Germany.
The 35-year-old from St Helens (36-4-1, 17 KOs) is used to being viewed as the underdog. When asked about that being the case against the unbeaten 28-year-old Saunders (26-0, 12 KOs), Murray said: 'It doesn't bother me.
'Come fight night I'll be the best I've ever been.'
Murray, who has been working with trainer Jamie Moore, added: 'My other four (world title fights) have been out of the country.
'Barring the Golovkin one (the only one that did not last 12 rounds), had they been in England, with the decision I think I would have got the fight.
'Now I have my fifth attempt and I am fighting Billy Joe, an English lad, in England. Everything is there for me now to go and fulfil my dream.
'I am really confident April 14 will be my night, that I will finally become world champion.
'He's flying at the moment, younger, fresher, but I've fought better people, have more experience, and I'm desperate.
'If I don't win I'm going to retire, and I don't want to yet. I want to win a world title, and a desperate man is a dangerous man.'