Boxing: Joseph Parker stuns Deontay Wilder in heavyweight fight in Saudi Arabia

Kiwi heavyweight boxer Joseph Parker became the underdog with the most powerful bite in Saudi Arabia on Sunday when he beat Deontay Wilder in the co-main event in the Day of Reckoning bout.

Parker made a mockery of pre-fight predictions that he would struggle to survive the 12-round fight in Riyadh, as he avoided Wilder's powerful right hand and turned the tables by repeatedly unleashing powerful punches to secure a unanimous point victory.

Dubbed the Bronze Bomber, Wilder was stunned by a disciplined and clever performance by Parker, in what was one of the most memorable victories in his career.

The three judges scored the fight in Parker's favour, returning scores of 118-111, 118-110 and 120-108 to reward him with the WBC International & WBO Intercontinental belts.

Parker, who had trained with Tyson Fury before travelling to Saudi Arabia, gave Wilder a lesson in how footwork, concentration, courage and powerful hitting can be a deadly combination.

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Joseph Parker celebrates victory with his medal and belt following the WBC International & WBO Intercontinental heavyweight title fight against Deontay Wilder in Riyadh, Saudi Arabia.

"He was a massive help,'' a jubilant Parker said afterwards. "What can I say? It all went to plan. I am back. I am ready for everything.''

Prior to the fight Parker, 31, promised to be the aggressor and after a tentative and cautious start he flicked a switch and set about pulling the plug on Wilder's hopes of a win to book a date with Anthony Joshua next year.

It was only the third time in Wilder's career that he had been forced to complete the full 12 rounds.

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Joseph Parker exchange punches with Deontay Wilder during the Day of Reckoning.

Wilder had a 43-2-1 record, which includes 42 KOs before this fight, but Parker wasn't intimidated, and in the 12, and final, round he continued to try to knockout the American.

For Parker (33-3; 23 KOs), this was a major step up from his recent bouts, but showed total disregard for Wilder's reputation.

Parker kept his distance in the opening rounds, a punch to the midriff of Wilder in the second being one of the highlights.

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Deontay Wilder (left) and Joseph Parker met in a heavyweight fight during the Day of Reckoning in Riyadh, Saudi Arabia.

Both fighters were hesitant with Parker attempting to land jabs to his lanky opponent before sparks finally flew in the fourth round as both men fired a flurry of punches.

The positive energy appeared to flow through Parker's veins as he connected with Wilder, several times steaming in with a one-two combination while remaining wary of the latter's powerful right hand.

Fears that Parker would struggle to penetrate Wilder's superior reach proved unfounded. Unlike Wilder, who was tentative as he appeared to wait for an opportunity to land a knock-out blow, Parker kept searching for chances to land punches.

After the fifth round trainer Andy Lee told Parker he had won each of them, and to keep jabbing at Wilder to accumulate points, and frustrate the 38-year-old, and after the sixth round the numbers were telling.

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Joseph Parker enters the arena for his ring walk prior to the WBC International & WBO Intercontinental Heavyweight title fight.

Parker, who was prepared to bide his time before unleashing clean shots, had landed 35 punches to Wilder's 16.

A right-hand by Parker connected with Wilder's head in the seventh, signalling he was capable of turning up the heat in terms of power and energy and in the following round he unleashed a flurry of punches much to the delight of the crowd.

Parker launched a series of over-hand rights to pin Wilder into the corner, going hell-for-leather to try and knock him out; the bell saved Wilder, but it was clear his legs were tired, and he was hurt.

With the fans now on the edge of their seats, and cheering on Parker, Wilder continued to play the waiting game; that motivated Parker to make him retreat with jabs to his chest and belly, knowing that if he could stay clear on the dynamite in Wilder's right hand, he could win.

By the ninth round it was clear Parker would only lose if knocked out. He had landed 44 powerful punches to Wilder's 17.

That told the story. Parker just had to survive the remaining rounds. He did. It was arguably the most memorable victory of his career.

Meanwhile, another Kiwi, Junior Fa, was stopped in the seventh round on the undercard by Cuban American Frank Sanchez.