Audley Harrison told Ringside he will silence his doubters when he faces the unbeaten David Price next weekend.
Twelve years on from his Olympic gold medal win Harrison will take on rising star Price for the Liverpool fighter's British and Commonwealth titles.
Harrison has failed to follow up that Olympic victory with big wins in the professional ranks and he knows this could be his final chance to prove he has what it takes to compete at the top level.
"This is definitely last chance saloon but this is my Indian Summer," said Harrison. "I've had a great training camp and I'm really looking forward to separating myself from the pack next week.
"David Price is a formidable test; he's 13-0 and hasn't put a foot wrong. But my training's been really tough. I've done 14 weeks and I've been sparring with Joe Hanks who's 20-0 and Malik Scott who's 35-0. So I've had tough sparring partners, I've tested myself and I've come through that.
"Training's been great, it really has. I've turned back the clock, for sure and I'm feeling really confident about next week."
Harrison says he has also been inspired by Team GB's Olympic boxers who enjoyed their most successful Olympic Games in over a century at London 2012.
"This summer I was among those Olympians; they were world class and giving their all for the medals. That was me, a world class athlete, and I'm definitely back to close the show my way," he said.
"I've always talked the talk but they don't give away Olympic gold medals - and I didn't just win a gold medal, I separated myself from the pack and won my fights handsomely. In this fight I'm going to show you how great I am."