A "grumpy" 75-year-old tried to plunge a diving knife into drinking pal's neck after an argument about gardening work flared at their local pub.
John Nyberg told his victim their friendship was "finished" after a row over gardening prices and stormed out of the Rose and Crown pub in South Shields, where they were drinking on January 4.
Newcastle Crown Court heard the pensioner, who has not been in trouble with the police since 1974, later returned to the bar, "full of hell", armed with the large weapon and tried to stab the 51-year-old.
Stunned customers who had realised what Nyberg was about to do, pushed tables into the elderly attacker's path and the victim managed to roll off his seat and escaped serious injury.
Nyberg, who has never been to prison before, is now starting a four years and four months prison sentence.
Prosecutor Jolyon Perks said Nyberg had already annoyed when he got to the bar that day, had said pubs were "robbing ********" before he started arguing with his pal.
Mr Perks said: "He was effectively re-visiting a disagreement they had about the cost of gardening work".
Mr Perks said Nyberg stormed off but then returned with the diving knife and added: "The defendant raised the knife above his head and brought it down in order to strike a blow into the neck.
"At the last minute, the complainant was aware of his presence and rolled off the seat in order to protect himself.
"He continued the attempted assault, waving blows with the knife in his direction."
The victim said the attack was "traumatic" and believed Nyberg was "trying to kill him".
Mr Perks said: "He genuinely believed he could have been seriously injured, if not killed."
Nyberg, of Prince Edward Road, South Shields, pleaded guilty to attempting to wound his victim with intent, possessing of an offensive weapon and common assault on one of the other customers who got injured during the struggle.
As well as the prison sentence, Judge Tim Gittins sentenced him to a five-year restraining order to keep him away from the pub and his victim.
The judge told him: "You were, it would seem, aggressive and grumpy that day, arguing about the pub and the price of drink.
"You challenged the complainant over a disagreement going on between you for a long period of time, that came to a head that day.
"You stood up and indicated your friendship, such as it was, with him, had come to an end and you left the pub.
"He, no doubt, thought that the argument was over and the incident would blow over.
"But, in fact, you clearly brooded on what happened and lost your self control."
The judge said Nyberg brought a "fearsome weapon" back to the pub and added: "His friends, realised what you were going to try to do, were turning over tables in your path.
"You managed to slash out at him, uncontrollably trying to stab him in the neck and others had to bravely intervene."
The judge said the attack could "easily have been fatal" and that the intended victim suffered minor cuts to his arms, fingers, and across his collar bone, which was a "real indication" of how close the blade had got to Nyberg's target.
Judge Gittins said all involved would have been "shaken and terrified" and added: "I suspect that the psychological damage of what you did will last substantially longer than the physical effects."
Vic Laffey, defending, said Nyberg worked all over the world during his years in employment and did not respond well to retirement or the breakdown of his second marriage.
Mr Laffey said Nyberg began to use drink to cope with his isolation and the development of mental health problems and lost interest in the healthy hobbies and habits he previously had.
Mr Laffey said: "He expresses regret for the incident.
"It is an extraordinary case.
"He is a man of 75 years of age. It is not often one comes across people of that age, who have never troubled the court for what is almost described as a lifetime, who end up involved in matters such as this.
"His time in custody has been a massive shock and had a massive effect on him, some of it positive."