An emotionally-charged Leon Edwards was held back by security as he faced off with Colby Covington before the pair's welterweight title fight at UFC 296 in Las Vegas on Saturday.
British champion Edwards weighed in at 170lb with American Covington 169.5lb.
The build-up to the bout has been marred by Covington's repulsive comment on Thursday that Edwards' late father is "in hell".
"That man [Covington] is as good as dead tomorrow," said Edwards.
"Make sure he keeps everything he said about my dad just… tomorrow, we settle it."
Edwards gave Covington a cold stare as soon as he walked on stage for the weigh-in before walking straight up to the former interim champion.
Covington goaded Edwards but the Birmingham fighter didn't say a word, instead choosing to continue staring at the American.
Edwards' body language was different to previous fights, where the 32-year-old often cuts a relaxed, reserved figure.
Angered by Covington's crass comment on Thursday, Edwards' emotions appeared to be close to boiling over as the pair faced off for the final time before their bout.
In an interview afterwards with the OceanNewsUK, Edwards said Covington's comments reveal "what sort of man he is".
"Obviously yesterday I was a bit emotional but it is what it is. I think it shows the character of the man he is and it makes it much more easier to go out there and hurt him," said Edwards.
"I don't want an apology. He said what he said. He's using my dad's death. As a man I'd never do that, I'd never speak of the dead, but that's who he is.
"I've spoken to my family, my mum and I have a great team behind me. I've got to be cold, stick to my game plan, listen to my coaches and secure victory."
Covington, grinning and interacting with the crowd, was greeted by a mixture of cheers and boos as he made his way on stage.
The 35-year-old is often brash and outlandish in the hope of garnering attention around his fights, but his comments about Edwards' father have drawn criticism from fellow fighters and pundits.
Birmingham's Edwards is making the second defence of his title after beating Kamaru Usman in March, while Covington last fought 21 months ago, defeating Jorge Masvidal.
Elsewhere, Liverpool's Paddy Pimblett and American Tony Ferguson both made weight for their lightweight contest.
Pimblett, 28, was booed as he walked on stage but embraced the jeers, grinning and encouraging the crowd to boo louder.
A fired-up Pimblett then shadowboxed before being greeted by 39-year-old Ferguson.
The pair were silent as they faced off, choosing to stare at each other with their fists held up.
Pimblett, who earned a narrow win over Jared Gordon one year ago, is fighting for the first time since ankle surgery in March, while former interim champion Ferguson is looking to halt a six-fight losing streak.
The co-main event sees a flyweight title fight between Brazilian champion Alexandre Pantoja and American Brandon Royval.
Covington comment left a sour taste - analysis
When Edwards has been asked previously what he thinks about Covington's persona, he has laughed it off, describing the American as a "clown" who engages in "harmless banter".
During the early stages of Thursday's news conference, Edwards displayed the same reaction - he was poking fun at Covington's George Washington outfit and laughing at his jibes.
But that all changed following Covington's crass comment about Edwards' late father.
Edwards, usually so calm and collected, snapped and tried to get to Covington before being held back by security.
Covington's comment left a sour taste which will linger until the pair meet inside the octagon on Saturday.
The incident raises questions about trash talking and whether it's acceptable for fighters to say whatever they want, no matter how despicable, in the name of selling a fight.
Edwards says the incident hasn't made things personal between the pair, but it will be interesting to see if it has any effect on the fight.
One of Edwards' biggest strengths is his patience and counter-striking ability, but if he goes in there trying to finish the fight too early, it could play into Covington's hands.
Edwards could swing too hard or over-reach which Covington can take advantage of with his takedowns.
On the other hand, if Edwards can stay calm and channel his emotion into his striking, Covington may regret giving the champion that extra impetus.
