Ovill McKenzie is ready to cause another shock by snatching away Victor Emilio Ramirez's IBF cruiserweight title on Friday night.
Jamaican-born hard-hitter McKenzie is in the Argentinian capital of Buenos Aires where he faces an arduous task against hometown hero and two-time world champion Ramirez (22-2-0).
With 12 career losses, McKenzie (25-12-0), who took the fight at just 11 days' notice, is the underdog but says he will draw on the experience of becoming Prizefighter champion in 2009, where he stunned the field after being drafted in two weeks before the event.
"I don't see this as my last chance to win a world title, I see this as my first chance to win a world title," McKenzie told Sky Sports.
"I don't mind being an underdog. I'm an underdog most of the time and most of the time I come out on top. That's how I got the name 'The Upsetter'. People have expected me to lose but I've knocked them out and won the fight.
"When I won the Prizefighter in 2009 I wasn't even on the poster because I was only added to the field two weeks before. I was also a light-heavyweight, I wasn't even a cruiserweight and I went in there and I did the business.
"I beat them all one-by-one and it was the best night of my career. Three fights, one night, prizefighter champion and £25,000.
"That experience made me realise I'm a true champion and that's when I truly started to believe in myself."
Two-time Commonwealth champion McKenzie had a hard upbringing, running away from home at the age of 13 and largely fending for himself on the streets of Jamaica.
But he says he would not change anything of his early struggles and hopes his rise in the sport can inspire the next generation of boxers.
"I don't want my kids to have to grow up the hard way like I did. I want to set a nice foundation for them so they don't have to suffer like me.
"God gave me the opportunity to be a boxer. I could never have imagined I would be fighting for a world title when I was growing up on the streets.
"But I knew I wanted the world to know me. I wanted people to know my name, I wanted people to know who Ovill McKenzie is.
"I've put in the work and it's good for young people to see I've come from the streets and gotten somewhere. It shows them there is a life out there for everybody. I'm a true fighter. I'm the poor people's champion."