Azlan King, 34, of Plymouth, Devon, was convicted by a jury at Exeter Crown Court of causing grievous bodily harm with intent. He was given a six- year jail sentence by Judge Graham Neville, who said he had turned Billy Wilkinson into a 'vegetable'.
Mr Wilkinson, 37, was beaten unconscious after he stayed too long with King's girlfriend, Serena King, last February, the trial jury was told.
He was left in a nearby car park, where he was later spotted and taken to hospital. He was put on a life-support machine after emergency surgery for jaw and rib injuries; he still suffers from slurred speech and lack of co-ordination, and may never work again.
King was jailed for five years for the attack and a year, to run consecutively, for wounding a motorist with a wheel brace after a road accident.