A thug who stabbed a man in the stomach outside a cocktail bar was later arrested after footage of the attack was posted on Snapchat.

Karn Martin lunged at Karl Duff with a blade as two groups clashed outside Captain Jack’s on Herne Bay seafront.

Martin, of Whitstable, ran from the scene but was traced after a video of the stabbing emerged on the popular social media app.

Now, the 34-year-old has been jailed at Canterbury Crown Court for four years after previously admitting wounding with intent.

The court heard Mr Duff was treated at a specialist London hospital after suffering a wound that penetrated his abdomen muscle.

A judge told Martin it was “a mercy” that Mr Duff did not sustain more serious injuries on that fateful night.

The court heard on Friday that Martin had been thrown out of the venue after throwing things towards a table where Mr Duff and his family were celebrating a stag do.

Peter Forbes, prosecuting, explained: “Martin and the group he was with made threats to the victim and his family, including threats to stab them and cut them up.

“As Mr Duff and his family walked outside, the two groups began fighting. Mr Duff felt it necessary to act in self defence and, for the safety of his family, he can be seen on CCTV throwing punches.”

Mr Forbes said the footage showed Martin holding a “shiny metal object” in his right hand while leaning over a rail.

He could then be seen lunging forwards, stabbing Mr Duff’s abdomen, and then running off following the attack in June last year.

The prosecutor continued: “Someone had filmed the incident on a mobile phone and it was posted on Snapchat.

“it came to the attention of police and the defendant was identified.

“Mr Martin later said he was too drunk to know what was going on.”

Mr Duff was treated at King’s College Hospital for four weeks while recovering from the wound, sustained below his rib cage.

He told the court of the physical pain he suffered following the assault, which has left left him with a one-inch long scar.

“The day after the incident was Father’s Day but, due to my injuries, I was unable to spend the day with my children, like I usually would,” he said in a victim impact statement.

“Instead, I was worrying that the stabbing would lead to internal injuries, and I kept worrying that my children would be left without a father.

“I also suffered financially as I had to take weeks off work while my injuries healed.”

The court heard Martin has a previous conviction for common assault and possessing a weapon.

Mitigating, Maya Chopra said Martin is a family man and apologetic for his actions.

“Since the incident, he has kept out of trouble and during that time he has had his third child, so the reliance by Mr Martin’s family on him has only increased,” she said.

“He has shown clear remorse and insight, and identified the problem as going out and getting drunk.”

But Judge Mark Weekes threw out the claims after finding an “inexorable inference that Martin left home that night in possession of a knife”, the court heard.

He told Martin, of Florence Avenue: “I sentence you on the basis that the knife was with you when you left your house that night, and that gives rise to very serious concerns by the court.

“I accept that your remorse is genuine, and I bear in mind that your children will miss you greatly during the time that you must spend in prison for this offence.

“You stabbed Mr Duff and it is a mercy indeed that a more serious injury was not done.”

Martin is expected to serve half of his term in prison and the following two years in the community on licence.