WBO heavyweight champion Joseph Parker (24-0, 18 KOs) is trusting that he's got more than enough punching power to put away IBF, IBO, WBA heavyweight champion Anthony Joshua (20-0, 20 KOs).

They will collide in their four title fight on Saturday night at Principality Stadium in Cardiff, Wales.

Parker is in top shape - which he reveals is due to undergoing several surgeries to correct a nagging problem with his elbow.

“We had restrictions with the elbow in the past,” Parker said.

“It didn’t allow us to train at 100%. But this time there are no excuses. If I win this fight, I’m the best in the world; if I lose this fight, then he is the best. The speed is back, the power is back and it is just about executing it on fight night.”

Last April, before a crowd of 90,000 at Wembley in London, Joshua picked up the biggest win of his career when he stopped former division ruler Wladimir Klitschko in the eleventh round.

Before he was stopped, Klitschko had Joshua down and in serious trouble during the sixth round. He was unable to put him away, and eventually Joshua rallied to scored two knockdowns to force the stoppage in round eleven.

If Parker finds himself in the same position, the New Zealand boxer is very confident that he will not allow Joshua to escape the round.

“I have prepared for 12 rounds hard with my coach,” Parker said.

“But I know if I catch him clean, he’s out. I am not going to give him a chance to recover. I am going to chase him hard and get him out of there. He looks angry and nervous. I am here to win and that is what I am going to do.”