• WBA and IBF champion prepares for defence in Cardiff • If I win this fight, then I’m the best in the world, says Parker

As the pounds have slipped off Joseph Parker during 11 weeks of hard training in Las Vegas, so the pounds have come in on the WBO champion to spring a huge upset when he faces Anthony Joshua in their heavyweight unification fight in Cardiff on Saturday.

But Joshua, who likes a punt himself and made £650 at the weekend when his former opponent Dillian Whyte stopped Lucas Browne in the sixth round, is convinced the smart money is on Parker’s fire raging and then fading around round eight or nine.

“The difference is I know how to counter-punch,” said Joshua, who puts his WBA Super and IBF titles on the line, with Parker putting up his WBO belt. “I haven’t seen Parker counter-punching anyone. I’ll punish him when he’s throwing at me, and I’ll punish him when he’s thinking of throwing at me. I’ll break him down.

“Rounds five to eight, it’ll be a tough night. But, if everything goes to plan I think Parker will fade between round eight and nine.”

After two ferocious and lengthy stare-downs between the pair at their final pre-fight conference Joshua revealed that he is trying to absorb and implement some of the lessons he learned from fighting Wladimir Klitschko last April.

“When I was facing off with him, he was saying: ‘OK, we have done this before and we turn to the front in five, four, three, two’,” Joshua said laughing. “I thought: ‘This motherfucker is experienced.’

“That was all about control. He was trying to out‑man me a bit. I thought I could look at Parker for 10 minutes but I decided no. When I was facing him off, it is about showing no fear but at the same time I thought: ‘How long will I stand here for?’”

There is something else that Joshua wants to learn from Klitschko – the capacity to stay always hungry and to improve. “I chat to Jonathon Banks, his old trainer, a lot,” he said. “I use the conversations as a way to speak to Klitschko. I ask how he continued to improve. Even in these good times we’re not satisfied.”

Joshua was also tempted to bid for a USB stick that Klitschko had sewed into his robe containing his pre-fight prediction for their contest at Wembley in April last year, which raised £160,000 for charity when auctioned in December.

Joshua said: “My auntie called me a week later: ‘I’ve got this flag from the Olympics, I was thinking about auctioning it off.’ I was cracking up. I didn’t bid for it. I thought 10 grand would be enough, thought I could be the silent bidder.”

Parker has looked unimpressive in his past three fights – winning decisions against moderate opposition. But he looked trim and noticeably less fleshy around the face – the result, he said, of having resolved elbow problems with “a couple of surgeries”.

“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.”

Parker was also dismissive about Joshua’s previous claim that no human can beat him, saying: “You can say it’s arrogance but it’s not realistic. Of course he can be beaten. He is not a god, he is a human being, and I will show on Saturday night that I am going to beat him.”

He insists that, if he has Joshua in trouble, as Klitschko did at Wembley last year, he won’t need a second invitation to put his opponent away. “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.”

When it was put to Parker that he had got under Joshua’s skin, he nodded. “He looks angry and nervous,” he said. “I am here to win and that is what I am going to do.”

The intensity in his voice suggested Parker meant every word of it.