A Boston drink driver brandished a claw hammer at another motorist who took his car keys from him, Lincoln Crown Court was told.
Juozas Gedvilas, described as hardly being able to stand up, left victim Presley Myers and his two teenage passengers terrified when he produced the weapon following a near collision between their vehicles.
Phil Howes, prosecuting, said the incident on Oxney Road, Peterborough, occurred after Gedvilas took a bend on the wrong side of the road.
"Presley Myers was approaching the bend when he encountered a car being driven by the defendant in his carriageway and driving straight towards him.
"Mr Myers slammed on his brakes. The other car braked too. They came nose to nose about two metres apart.
"The defendant was seen slumped over the steering wheel. Mr Myers went to check on the driver. The defendant mumbled a few words and smelled strongly of alcohol.
"Mr Myers accused the defendant of drink driving and describes him as being all over the place.
"Mr Myers removed the keys from the defendant's vehicle and the police were called. The defendant could hardly stand up when he got out of the car."
Mr Howes told the court that Gedvilas demanded his car keys back but his request was refused and he then went to the boot of his car and returned with a hammer.
"The defendant gave him a count of one, two, three and then ran at Mr Myers and swung the hammer at his head.
"He missed and Mr Myers backed away. Gedvilas then turned his attention to the two teenage girls. He started walking towards them and they ran off. They were scared. One of them thought he was going to kill them."
Police then arrived and detained Gedvilas. He failed a breath test with the reading being 116 mgs of alcohol per 100 mls of breath putting him more than three times above the legal limit of 35 mgs.
Gedvilas, 55, of Hartley Street, Boston, admitted charges of affray, driving with excess alcohol and driving without insurance as a result of the incident on 27 May last year. He was jailed for eight months and banned from driving for 16 months.
Judge Simon Hirst, passing sentence, told him "This was unprovoked seriously threatening violence in the street. It involved innocent members of the public who behaved in a public spirited way. They must have been terrified. It is only due to Mr Myers backing away that you didn't hit him with the hammer causing who knows what injuries."
Leanne Summers, in mitigation, said that Gedvilas has expressed remorse for what he did and apologised.
"Thankfully nobody was injured. Mr Gedvilas tells me that he had no intention of using the hammer to cause injury."
Miss Summers said that Gedvilas is currently undergoing treatment for a heart condition and she urged that any sentence of imprisonment should be suspended..