Leapai stands on brink of history

He's done drugs, alcohol and even time behind bars, but now Alex Leapai wants to be Australia's first universally recognised world heavyweight boxing champion.

When the 34-year-old enters the ring in Oberhausen, Germany on Sunday morning (WA time) to challenge the mighty quadruple title holder Wladimir Klitschko, he has the chance to secure one of the few major prizes to have eluded Australia.

A win over hot favourite Klitschko would allow him to join the likes of golfer Adam Scott (2013 US Masters) and cyclist Cadel Evans (2011 Tour de France) as Australian drought-breakers in capturing some of sport's most prestigious prizes.

"Aussie" Joe Bugner, everyone's favourite Hungarian-British-Australian boxer, will tell you he already holds the distinction.

But the WBF title he won in 1998 wasn't recognised by the vast majority of the boxing world.

Kali Meehan, who sparred with Leapai in recent weeks, came agonisingly close to winning the more established WBO title in 2004 when he lost a split decision to Lamon Brewster in Las Vegas.

In three months in 1908, Australians Bill Lang and Bill Squires had, between them, three unsuccessful cracks at wresting the world title from Canada's Tommy Burns.

Now it's the turn of Leapai, who has been branded the Australian Rocky Balboa by Klitschko, who, with a 15cm height advantage, is the Goliath in this matchup.

There was no early sign of global boxing glory for the Samoan-born power puncher, who won just one of his first four professional fights before linking up with trainer Noel Thornberry almost 10 years ago.

Leapai has lost only three of 33 under Thornberry's stewardship and one of his past 23, with 17 of his 21 wins in that latter phase coming via KO.

Thornberry turned around Leapai's career, but it took a while before the Queenslander turned around the rest of his life.

In recent months, Leapai has candidly documented a dark decade during which he had alcohol and drug problems and spent six months in prison for assault.

Before that, a promising rugby league career was nipped in the bud when the former North Queensland Cowboys scholarship holder was banned for five years for attacking a referee.

Having emerged from those tough days, the father of six craves the belt as much for the children he hopes to inspire as he wants it for the million-dollar plus pay day.

"I've been inside (jail), (done) drugs, alcohol and been able to walk away from all that stuff and just go the right path," the 34-year-old said.

"It's so important for me to win this fight just for the kids.

"I've had a pretty bad past and the great lord, the heavenly father, has given me a second chance and I just want to prove it that we can do anything."

A shock win over No.1 WBO contender Denis Boytsov in his last bout propelled Leapai into a matchup with Klitschko who is riding a 10-year, 19-fight winning streak.

Thornberry, whose assistant in the corner is his brother and former super-middleweight world title contender Rick, spotted Leapai's potential as early as his third paid bout.

"I said to Ricky, 'See that bloke there - if he was serious and wanted to go all the way, he'd probably fight for the world title'," Thornberry told AAP.

"All I had to do was make him as good as he can be.

"Everyone was saying, 'He doesn't bob; he doesn't move; he will never be a classical boxer'.

"I always said to him, 'Listen, you've got strengths; you've got physical strengths - your power - you're very tough.

"Your weaknesses are experience and your cardiovascular and that all stems from diet, so we changed his diet."

The diet might have changed but the hunger is undiminished.