Zhilei Zhangs explosive right hook was enough to knock out Deontay Wilder in the fifth round of their showdown in Riyadh on Sunday.

Both fighters were looking to make a statement in this bout as their respective losses to Joseph Parker had raised doubts over their ability as contenders for the heavyweight crown.

Zhang looked the more likely to score a knockout with a flurry of punches and a big right hook in the second round to send Wilder to the ropes.

Wilder tried to start spritely in the fourth and fifth rounds, but he lacked that lethal punching prowess he is known for instead opting for a more cautious approach.

The former WBC champion would eventually succumb to the constant pressure from the Chinese as he fell to the canvas, leaving him dazed and facing a seemingly impossible recovery battle.

The American tried to beat the referees count but was left on the receiving end of a devastating stoppage.

Wilders proposed fight with Anthony Joshua now looks unlikely as many speculate the former champion is considering retiring. (AFP)