Jurors who found David Powell guilty of the killing of 37-year-old Gerard Adeshida in Beeston were told that he has a previous conviction for killing a man a decade ago in an attack in the same area of the city.
Powell, 27, punched Mr Adeshida in the jaw on Ladypit Lane just after 6pm on August 23 this year.
Mr Adeshida fell back and hit his head on the road, causing a skull fracture and fatal brain injury.
Powell, of Clovelly Grove, Beeston, denied manslaughter, claiming he was acting in self-defence, but was unanimously found guilty by the jury of eight men and four women at Leeds Crown Court.
Mr Adeshida and his identical twin brother Keiron had been drinking strong cider before going out walking in Beeston on the day of the attack.
Powell was driving in his new car with three friends and they were playing loud music.
The jury was told Mr Adeshida swore loudly at the car as it passed as he believed the occupants were making fun of him.
The car slowed and Keiron Adeshida apologised to Powell, but his brother carried on swearing.
Powell stopped the car in the middle of the road, jumped out and approached the brothers with his fists clenched.
Mr Adeshida, who had lived with his twin brother all his life, tried to defuse the situation but Powell remained angry and punched him to the jaw.
Powell claimed to have stopped the car because there was something wrong with it and saw two men approaching him aggressively.
After the verdict, the jury heard how Powell had served a three-and-a-half-year sentence for manslaughter for a fatal attack on a man in 2004.
Powell, then aged 17, laid in wait for Kelvin Jukes, 26, as he left a shop in Trentham Street, Beeston, Leeds, after an earlier confrontation during which the older man hit him. Mr Jukes, who had been drinking, tried to run away but Powell caught him and punched him, causing injuries to his left cheek and right eye.
He fell and suffered the fatal head injury, including bleeding around the brain.
Mrs Justice McGowan adjourned the case so Powell can be assessed as to whether he poses a serious danger to the public. He will be sentenced on February 6.
The judge said: “For the second time you have set about the chain of events that has caused the death of a person.”
After the case, Det Supt Nick Wallen, of West Yorkshire Police Homicide and Major Enquiry Team, said: “Gerard Adeshia’s death was completely unnecessary and was the result of the briefest moment of violence. This case tragically illustrates the devastating consequences that throwing just one punch can have.
“Mr Adeshida’s family continue to suffer their loss and are facing their first Christmas without him.
“I would like to take the opportunity to remind people, particularly at this time of year when people will be out to celebrate over the festive season, of the serious consequences that just a moment of violence can have. No matter what the perceived provocation, it is always better to take a deep breath and turn and walk away.”