Martin Davis, 27, was incensed at rumours allegedly being spread by the victim that he had been sleeping with another woman behind his partner’s back, York Crown Court heard.
Prosecutor Jeremy Barton said Davis saw the victim go into a property in Scarborough where a group of friends had gathered.
Davis stormed into the house, dragged the man out into the back garden and threw punches at him. The victim ran away but fell, whereupon Davis sat on his back and punched him three or four times to the face and head.
The terrified victim ran to a neighbouring address where the occupant was said to be “shocked and appalled” at his condition.
Police were called to the scene and arrested Davis.
Mr Barton said the victim suffered multiple facial injuries including a fractured jaw and swelling to his eyelid, which had closed up.
He had to undergo surgery to have a plate and screw fitted to his jaw.
Davis, of Seamer Road, Scarborough, appeared for sentence on Tuesday after pleading guilty to assault occasioning actual bodily harm.
Defence barrister Taryn Turner conceded that it was a “disgraceful, ugly” attack, but said Davis was in a “bad place” at the time because his relationship with his partner had broken down, he had lost his home and was finding it difficult to cope.
He was currently serving an eight-month sentence after being convicted of criminal damage in October last year.
Davis was jailed for 21 months and was ordered by the court to pay a victim surcharge.