"Tonight I knew I was going to win the fight, but not in that fashion ... but I knew if I caught Barrett he would go over and he did go over and never got back up," said Cameron.
"It will open up a lot more doors in the heavyweight division.
"In terms of making predictions about who I want to fight next, that would be a stab in the dark really, but there will be some good things coming out of this."
Cameron, looked fit and focused before the fight but it was his power more than anything which surprised everyone, including Barrett.
He had prepared for the bout by sparring with David Haye in London, a move which was ridiculed by Barrett, who said Cameron must have "psychological problems" for doing so.
"I didn't want to shoot my mouth off beforehand, that's not my thing," said Cameron. "The Haye camp was a good wake-up call for me. It brought my skills back. Coming back you're always going to have your critics, saying 'you shouldn't have gone', but it was probably just Barrett more than anything, he was probably worried how much I benefited from it. I've learned so much from it."
The first round appeared even, but Cameron had the better of the second and third rounds before dropping his bomb straight down the middle only seconds into the fourth.
"It probably educates the public a bit more about how one punch can change a fight.
"Look what David [Tua] did to me in that first round with that one punch. He didn't put me to sleep but I couldn't recover. What one punch did to Barrett tonight - he was asleep, he doesn't know where he is. Even after the fight he doesn't know where he is. That just shows you how brutal the sport can be. It's not a nice place to be."
Cameron said as soon as he hit Barrett he knew he wouldn't get up and will now hope to work his way to a title shot against one of the Klitschko brothers - Wladimir or Vitali - or possibly former sparring partner Haye.
He said a rematch with Tua didn't interest him.
"It's a hard fight against the Klitschkos, but again it's an opportunity. A lot of people wrote me off tonight, they didn't think I was going to win but I won in great fashion. You just don't know what's going to happen on the night."