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.'
Murray has no doubt he does 'not have long left' regardless of how the contest pans out and intends, if he does win, to have two further bouts before retiring, which he expects to be a rematch with Saunders plus 'a big fight with whoever'.
He is still having sessions once a week with his long-term trainer Oliver Harrison, who has been seriously ill.
But most of Murray's work is being done with ex-European light-middleweight champion Moore, his former sparring partner, at the Astley gym that Belfast's former two-weight world champion Carl Frampton is also now training in.
'Oliver is recovering. It is not really up to me to say exactly what has gone on, but he's been through a bad time and the fact he's alive is a miracle,' Murray said.
'I was with him last week, and I'll be in again with him on Thursday. But it was just the natural place to come, working with Jamie.
'When I started with Oliver, Jamie was flying then and some of the spars we used to have were brutal. I learned a lot from Jamie and we've always been close.
'I've always rated him as a coach. It doesn't feel weird at all. He's always been someone I look up to, and it's the same now.'