Arthur Jepson, aged 66, of Manor Road, Harlington, was accused of attempting to murder his neighbour, Nicholas McNaughton, during a fight about a garden fence in March this year.
However, after a week-long trial at Sheffield Crown Court, the jury decided Jepson was acting in self-defence, acquitting him of attempted murder and of wounding with intent.
But he was jailed for three months having previously admitted producing the class B drug cannabis.
Sheffield Crown Court heard the pair had been friends, but in 2012 the relationship between them soured and the police had been called out to intervene in rows on other occasions.
On the night of the stabbing, Mr McNaughton had thrown a fence panel onto Mr Jepson’s land, which he threw back.
Gordon Stables, defending, said Mr McNaughton then pushed Jepson to the ground and started punching him repeatedly.
Jepson stabbed him in the arm using a nearby knife, which he had been using for gardening earlier in the day, to make the attack stop.
Addressing the jury, Mr Stables said: “Mr Jepson did not go for a vital area, like the head or the chest. That will perhaps give you some idea of the level of intent.
“The law allows for self-defence. If a 16-stone person is sat on your chest and the attack is ferocious and going on and on, the law does not expect you to take it.”
After the incident, both men returned to their houses and called 999.
In a recording played to the court, Mr Jepson admitted to the operator that he had stabbed Mr McNaughton with a knife, which he estimated to be five inches long.
He said he was still holding the knife and did not want to put it down because Mr McNaughton ‘might come out of his house with a bigger knife’.