CHEV CLARKE blew Chris Billam-Smith off the air with an explosive seventh-round stoppage to complete a hat-trick of wins over his old amateur rival.

The man nicknamed C4 detonated a devastating overhand right that sent the former WBO cruiserweight world champion crashing to the canvas at London’s Copper Box Arena.

It was the first time Billam-Smith had ever been floored since turning professional.

Billam-Smith bravely beat the count but was left stumbling as Clarke unleashed another vicious assault that dropped him once again, with a final blow eventually forcing the referee to wave off the contest.

And Clarke, 35, celebrated by throwing his arms out and shrugging his shoulders in triumph after producing a box-office explosion that left CBS without a clue.

It was the third time Clarke has beaten his British rival, having twice defeated him in the amateurs in 2016, including in the English National Championships final.

The electric Copper Box felt like a proper British derby, with fans singing the name of Billam-Smith – dressed in all black – as the Bournemouth favourite marched forward against Clarke, who was kitted out in all white.

The bigger Billam-Smith started on the front foot, working the body and forcing his way inside as both men initially felt each other out, just as they had a decade earlier.

But the action soon became more wrestling than boxing, with both fighters clinching and trading thudding body shots that could be heard from ringside – they might as well have been fighting in a phone box.

Billam-Smith was determined to impose his size and strength, while the smaller Clarke tucked his head beneath his rival’s chin and relied on his speed and agility to bounce in and out of range.

And in the fifth, Clarke began finding his rhythm, landing three sharp jabs before rocking CBS with a beautiful right hand and following up with another two as the sweat flew from his rival’s head.

Billam-Smith continued hunting him down in the sixth, digging hooks into the body and landing a thunderous shot that sounded like a double-barrelled shotgun going off .

But Clarke fired back with another overhand right and even beckoned his opponent forward.

That proved a dangerous invitation to accept – Clarke’s overhand right was the weapon Billam-Smith simply could not escape.

And when it ultimately exploded in the seventh, not even instructions of composure from trainer Shane McGuigan could save him from a sensational defeat.