Former heavyweight champion Mike Tyson slapped opponent Jake Paul as the two men faced off for the final time on Thursday ahead of their controversial Netflix-backed bout.

Tyson, 58, hit Paul flush on the cheek with his right hand following the formal weigh-in for Friday's fight at AT&T Stadium in Arlington, Texas.

A scrum of security swiftly intervened to separate the two fighters following the incident before Tyson was ushered away.

Tyson, who weighed in at 228.4 pounds after stepping onto the scales wearing only a pair of Versace briefs, barely spoke before leaving the stage.

"Talking's over," Tyson said before making his exit with members of his entourage.

Paul, the 27-year-old Youtuber-turned-boxer, insisted he had not been hurt by Tyson's open-handed slap, which drew gasps from the audience.

"I didn't even feel it -- he's angry. He's an angry little elf...cute slap buddy," said Paul, who weighed in at 227.2 pounds.

Paul concluded his remarks with an expletive-laden pledge to knock Tyson out, before roaring theatrically into a microphone: "He must die."

Tyson is reportedly being paid $20 million for Friday's officially sanctioned bout in Texas, which will be comprised of eight two-minute rounds.

The contest, being streamed live on Netflix, has divided opinion across the boxing world, with many prominent figures decrying the prospect of Tyson lacing up his gloves nearly 40 years after his professional debut and 19 years after his last officially sanctioned fight.