Joseph Parker insists he remains on a different level to Fabio Wardley, and vowed to "smash him" ahead of their bout this weekend.
The New Zealander and the Briton meet at London's The O2 Arena on Saturday live on DAZN Pay-Per-View in a major heavyweight bout.
With the winner likely to face Oleksandr Usyk for the division's undisputed title next month, both men are keen to lay down a statement victory.
But speaking at Thursday's press conference, Parker reiterated his belief that he is a bridge too far for Wardley to conquer inside the ring.
"For me, this is all or nothing," he said at a relatively respectful media event. "I'm not thinking about losing this fight. I'm going into this fight to win.
"Once I win, I'm going to move onto the next fight. I respect my opponent, what he has done in his career, how he has prepared for this fight.
"But I'm a different level, to be honest, and I'm going to show it on Saturday night. I don't want to explain with words, I want to explain with actions.
"I've many more miles on the clock, and I've many more miles to bring. I'm only getting into my prime now. It's the wrong time to take this fight.
"It's the wrong time to take this fight because I'll smash him. He's going to learn that it's OK to have a loss and that he's got enough time to come back."
Joseph Parker and Fabio Wardley fight on Saturday, October 25, to become the WBO mandatory challenger to Oleksandr Usyk. Watch the fight and undercard live and exclusive on DAZN PPV.