'Iron' Mike knocked out by children's toy

Former heavyweight champion Mike Tyson once ruled the ring with an iron fist.

These days he struggles to even overpower a children's toy.

The "greatest fighter who ever lived" was out for the count when he embarrassingly became the latest victim of the most desired toy on the market – the 'hoverboard'.

In a video posted on Instagram, the 49-year-old can be seen gleefully operating the new device, clapping his hands in delight as he executes a number of spins.

However, his fortunes were to change quicker than some of his famed knockouts, moments after his daughter warned him of the perils of the machine.

"Daddy, I don’t want you to fall," Tyson's daughter tells her father.

Not heeding the warning, Tyson loses his balance, slips from the machine and slams painfully into the hard wood floor.

There is no word yet of a potential rematch.