Kevin Mitchell admits he will be in the last-chance saloon when he takes on John Murray in a world title eliminator at Liverpool's Echo Arena on Saturday.
The much-anticipated lightweight bout will be Mitchell's first since he was beaten in three rounds by Australian Michael Katsidis in May 2010.
The Dagenham fighter, 26, paid the price for personal problems that marred his preparations for that fight.
"I see this as my last chance for the big time," said Mitchell.
"That is why I am going to go in there on Saturday and show that I am here to put in a massive, explosive performance. That is why you are going to see me at my best."
Mitchell embarked on a six-month drinking binge following his defeat by Katsidis before returning to the gym.
And now the former British and Commonwealth super-featherweight champion faces Manchester's Murray knowing the winner is set to take on WBA champion Brandon Rios - and he is determined to make the most of the opportunity.
Mitchell (31-1, 23 KOs) said: "People keep saying this is a 50-50 fight, but if I had beaten Katsidis by performing the way I should have done, this fight wouldn't even be happening.
"John is a good fighter, but they would be calling this a mis-match, because I have been fighting at world level and he hasn't. Because I have been beaten, they are now doubting me, but I'll show on Saturday it's not a 50-50 fight."
However, Murray (31-0, 18 KOs) believes Mitchell will be the one trying to keep up with a superior opponent.
"I think I've had tougher fights throughout my career and better wins," said Murray, a former British and European lightweight champion.
"You can say Kevin has boxed at a higher class, but he only did that once and got beaten in three rounds. I see myself as a step up in class for him and I'll show him why on Saturday night when I knock him out."
The vacant WBO Intercontinental title will be up for grabs in the contest, which is the main attraction on the undercard of WBO super-featherweight clash between Scotland's champion Ricky Burns and former title-holder Nicky Cook.