In three months, Alex Leapai from Logan, Queensland, will box in the footsteps of gods, share a piece of sporting history with Muhammad Ali, Mike Tyson, Joe Frazier and Joe Louis. “On April 26, the whole world will know the bloke who was a truck driver six months ago who walked in and won the world championship,” Leapai says.

“Mysterious ways, bro,” says Leapai. He shakes his head, shrugs. “Storm comes, you keep going. Nothing can stop it.” His white gym shirt is soaked in sweat. He moves to a ­corner of the ring, takes a water and a breather. “He has the belief,” says Thornberry.

If Alex Leapai’s suspicions are correct it was God who made all this, constructed this Cinderella tale of the 34-year-old delivery truck driver and father-of-six with a rank outsider’s chance to become the heavyweight boxing champion of the world in Germany on April 26. Perhaps it was also God who made his trainer Noel Thornberry and sent the terrifying summer storm that ravaged Thornberry’s tin shed gym only four days ago, tore up his family property, lifted a 20,000-litre water tank from its roots and bashed it a kilometre across a neighbouring lucerne field.

Australia’s first world heavyweight boxing title contender in 106 years flexes his left calf muscle, powers energy into his hulking right thigh muscle, propelling his right hip forward, pushing a right shoulder the size of a full leg of ham into motion, driving his right overhand punch diagonally down from above, fist into pad, knocking his wiry trainer off balance. The punch drills so deep into the pad that its innards are too broken, too spent to bounce back for more. Another pad for the bin.

He bobs, stalks around the ring, prowls. And there’s the bang, a five-punch cracker-night combination into a punching pad. The hardest punch in world boxing hitting padded leather sounds like a fireworks pontoon exploding.

If God sent him to prison then God sent his beloved wife Theresa to save him from dying in there.

If God made his right arm, charged it with lightning and thunder to drive his jackhammer overhand punch, then God made his small fingers that keep breaking.

The contender

The training ring, made of four thick ropes, shares space in Thornberry’s backyard shed with a collection of rusting weight benches and exercise machines. A battered red lawnmower and an old bicycle belonging to Thornberry’s wife, Jan, rest by a work bench near the ring. It’s early morning and Jan is still in her pyjamas, across the yard in the house with their five kids. Leapai drives two hours to get here, sometimes three times a week, from his home in working-class Logan, south of Brisbane. Only six months ago he was squeezing that routine between work shifts, hauling a truck filled with aluminium door frames and windows for office fitouts across the city. “This is old-school,” he says, looking around the shed. “This is Muhammad Ali.”

Thornberry and Leapai

“This is old school ... This is Muhammad Ali.”

Thornberry, 47, swigs from a water bottle and steps out of the scorching heat of the tin shed. “That’s it over there,” he says, pointing across his property in the Lockyer valley, 90km west of Brisbane, to a distant pile of metal rubble that was once his water tank. He points to trees snapped in half; pyramids of gathered debris ready for removal. “We’re waiting for the insurance to come through,” he says. He shrugs. “But that’s the least of our problems.” Their biggest problem is a Ukrainian colossus named Wladimir Klitschko. The current world heavyweight champion has a face like Abe Lincoln’s – not as it looks in history books, but as it looks on Mt Rushmore, made of rock. Klitschko has won 61 of his 64 professional fights, 51 by knockout. He’s the second-longest reigning heavyweight champion of all time, dominating his division for a decade; number three on history’s list of most heavyweight title fights, behind two geniuses, Joe Louis and Muhammad Ali.

At 198cm, Klitschko is 15cm taller than Leapai and has a huge 16cm reach advantage. He has the ringside presence of Frankenstein’s monster. “Dr Steelhammer” they call him. He’s whip-smart in the ring, a master technician. Online boxing forums play videos of Klitschko’s greatest hits package, a dizzying montage of right and left hooks that leaves the viewer wanting to vomit. There’s a round seven knockout blow that he landed on Calvin Brock in 2006; in the slow-motion replay (see below) Brock’s mashed face goes in three distinct directions before he drops, left to egg-flip his lips from the canvas like David Hasselhoff on a drunken burger urge. He’ll drive six left hooks into a fighter’s face in the time it takes a man to open his mouth and voice the word, “Towel”. Below these videos, fight fans post comments like, “Leapai’s gonna need to take a shotgun with him… he’ll be KO’d inside three”; “Klitschko gonna smack this boy up, down and sideways.”

When Sportsbet listed Leapai’s chances at 24-to-one to win by knockout, the media contacted Noel Thornberry. “You got a message for Sportsbet?” they asked. “Yeah,” said Thornberry. “Sack your odds maker. He’s a moron.” He knew things Sportsbet didn’t: that even though Leapai’s record stands at 30 wins (24 by knockout), four losses and three draws, there’s no true form on the Logan boxer; that he’s never before had the time and money to train and prepare like he is now; that most of his boxing career has been spent juggling shitkicker warehouse and delivery jobs to feed his six kids while scratching around for sparring partners foolhardy enough to step into the ring with him. And that the fight that saw the eighth-ranked Leapai become the World Boxing Organisation’s mandatory world title challenger – the miraculous points win last November over the previously unbeaten Russian Denis Boytsov – was won carrying a torn calf muscle.

Boytsov vs Leapai (Nov 2013)

“Klitschko’s been in 64 fights,” Thornberry says. “He’s been knocked out three times. I think sometimes champions become impatient, slash arrogant. Nothing is a challenge. They read too much of their own media. They read the write-ups and they believe them. They think they’re invincible.” Thornberry points his water bottle at Leapai. “But the other bloke happens to be the hardest puncher in boxing. And we’ve got three months to eat, sleep and breathe Wladimir Klitschko.” Leapai has a show-reel too: a series of punishing uppercuts and hooks that would remove heads from granite statues. Thornberry holds up his right forefinger and thumb to Leapai, leaving a gap between his fingers of an inch. “This is what separates you from being the world champion,” he says. Leapai nods. “That can be anything. That can be diet. That can be sparring. That can be intensity toward your training. That can be consistency. That can be belief. There’s only this much between champions.” Trainer and boxer return to the centre of the ring. Leapai prowls, rolling his shoulders, bobbing his head. If Klitschko is an artist like Ali, Leapai is a mongrel like Tyson, in your face, never letting you breathe, always working you around the ring, rolling you toward exhaustion, with a holstered power punch like George Foreman. Leapai sees a glass jaw on Klitschko. He smells it on him, sniffs it with his flared nostrils. “Once he feels what I’ve got, mate, he’s gonna fight to survive,” he says. “It’s just a ­matter of time. Bang. Fight finished. And we all just come home.”

All the rough odds in the world mean nothing to a miracle punch, a single knockout blow from the right fist to send Alex Leapai into sporting history. All he needs is an opening. All he needs is an inch. “He cannot handle Alex’s power, I guarantee you,” Thornberry says. “It’s a matter of Alex being able to hit this guy.” “Once he feels what I’ve got, mate, he’s gonna fight to survive,” Thornberry wraps his arms around Leapai’s head. “He’s gonna try and use your head,” he says. “If his head’s on your head, he’s safe.” Thornberry rests his head into Leapai’s neck. “He’s going to get it here so you can’t get him. So you have to time it.” He steps back sharply, throws a swift uppercut. “Whack,” he says. “It’s not about power, it’s about accuracy. If he’s walking forward, keep it short. Keep it as close to your body as you can. Straight up against the forces of gravity. Boom.”