Tom Arnold and Dean Cain almost came to blows after they Twitter feud boiled over into real life.

The actors met backstage at Larry King's studio on Tuesday and footage shows them arguing, their faces just a few inches apart, over an incendiary tweet sent by Arnold last month.

Arnold had called out Cain on Twitter, for appearing at the Values Voter Summit - hosted by conservative Christian group The Family Research Council.

'Dean Cain is another Donald Trump loving, fake Christian coward which makes Dean Cain anti-LGBTQ and racist #complicit,' Arnold tweeted on September 23.

Tom Arnold and Dean Cain almost came to blows after they Twitter feud boiled over into real life

'Tom, you're a cowardly, slanderous weasel,' Cain hit back on Twitter.

When they met in person, sparks began to fly.

The cellphone video, obtained by the Hollywood Reporter, begins mid-argument with Cain, a Trump supporter, who is best known for his role as Superman in the New Adventures of Superman television series, insisting: 'I'm not a racist person; I never have been.'

'I've always supported gay rights,' Cain said. 'Let me finish for a second. You're giving me guilt by association.'

Yet Arnold, who has become increasingly outspoken on politics in recent years, likened The Family Research Council to 'Nazis.'

'They're hurting people. You know how many suicides of f**king gay kids? They f**king shame them and they try to keep them out of f**king schools,' Arnold argued.

'Please hear me. I don't want those f**kers using you.'

'Nobody is using me. I speak my mind,' Cain countered.

Tom Arnold (left) and Dean Cain (right) met backstage at Larry King's studio on Tuesday and footage shows them arguing, their faces just a few inches apart, over an incendiary tweet sent by Arnold last month

A witness claims there were fears that the argument could escalate into violence.

'Dean was intense. He looked ready to do something if Arnold came at him,' said the witness, who filmed in secret after being ordered to put their phone down.

The footage ended with the pair hugging it out, but it appears the fight was not over.

Cain later tweeted: 'He called me #racist and said I was anti-LGBTQ. Totally untrue. After I confronted him, he backed down. That's how it always seems to work.'

Arnold had a different version of events, telling THR: 'I was giving him a break by not assuming he was stupid about the FRC, which I do liken to Nazis, and now I see he's one of them.'

Cain was at the studio in Glendale, California, to appear on Larry King Now to promote his anti-abortion film, Gosnell: The Trial of America's Biggest Serial Killer.

Arnold was there to promote his series The Hunt for the Trump Tapes With Tom Arnold, which airs on Viceland.