Paul Gallen: I will knock Sonny Bill Williams out

Cronulla captain Paul Gallen. Photo / Getty

Sonny Bill Williams lit the fuse last month for a super fight with Paul Gallen, now the Sharks skipper has delivered the imminent explosion by declaring 'I'll knock him out'.

Speculation the pair would meet in the boxing ring has lingered for some time without any real development, until Gallen said on Sunday he is ready to 'get it on' with the rugby star.

"About Sonny, it's been spoken about for four or five years," Gallen said on Sports Sunday.

"The first year or two I was a little bit hesitant to do it but certainly the past two or three years I've said 'let's get it on'.

"He's finally come out in the last month or so and said he's willing to do it.

"I will knock Sonny Bill out."

Gallen then went on to further prod the fire by saying SBW has had much of his career handed to him.

"Sonny has had everything go his way since he's been 14 years old. Contracts go his way, that's the problem at the moment is we're trying to negotiate but they want it all their way.

"I bring as much to this party as Sonny does."

The All Blacks World Cup winner declared his genuine interest in the fight last month.

"I've heard for some time now he has wanted to fight me," Williams said.

"Well, provided we both get through our seasons OK, he will get what he wants. I don't back away from challenges. Let's get this thing cooking."

Williams is undefeated in his boxing career, boasting a record of seven wins, three by knockout and zero losses.

His career highlight to date was against former South African heavyweight champion Francois Botha in a controversial "10 round" win in February 2013.

Gallen has a career record of seven wins, four by knockout and zero losses, most of which came in charity bouts against NRL stars.

The latest was his brutal three round win against Canberra Raiders enforcer Junior Paulo in December last year.