Dereck Chisora is to take on Robert Helenius for the vacant European heavyweight title next month.
Londoner Chisora, 27, will fight the undefeated 'Nordic Nightmare' in Helsinki, Finland on 3 December.
The bout will be the Finchley fighter's second since losing his British and Commonwealth titles to Tyson Fury.
Chisora said: "Believe me, this is the biggest mistake they have made with his career and I'll be going over to Finland to knock him clean out."
Finland's Helenius, 27, is unbeaten in 16 fights and has knocked out 10 of his last 11 opponents, with bouts against former world champions Siarhei Liakhovich, Samuel Peter and Lamon Brewster all ending in early stoppages.
Chisora returned to the ring in Halifax on 11 November, beating Remigijus Ziausys over six rounds.
Chisora said: "He's called the Nordic Nightmare, but he'll be having nightmares about me for the rest of his life after I've left him flat out on the canvas.
"I'll be fit and ready for this fight like never before, it's the big fight. I need to really get my juices flowing and performing like I know I can."