Charles Martin says he will stop Anthony Joshua when the pair clash in Saturday's heavyweight showdown at the O2 Arena.
Martin will put his IBF title on the line for the first time against fellow undefeated rival Joshua in front of 18,000 fight fans, live on Sky Sports Box Office.
The American has secured 21 of his 23 wins inside the distance and is confident of adding Olympic champion Joshua's name to his list of victims.
"It's not going the distance," Martin told Sky Sports News HQ.
"It only takes 10lbs of pressure to knock a man out and he's an elite athlete so it might take a couple of more pounds but I know I'm hitting with at least 900lbs of pressure.
"I can whack, I'm not just a pure puncher, like all I can do is punch, I've got more stuff to me, but I can definitely knock people out, I can definitely whack.
"I just wait for the opportunity and when I see it, I'll whack him, I'll sting him and stay on my game."
Southpaw Martin turned professional at the relatively late age of 23 after quitting his job as a construction worker.
"I'm here to stay, it ain't a game, I came this far and I'm going to keep it going. I came too far, my whole life has been changed.
"I've turned my whole life around, anyone can turn their life around if you're heading down the wrong path or you're not happy with where you are if life, only you can make the change."
