Keith McCardle, 51, consumed four alcoholic drinks in the hours before getting behind the wheel of his Land Rover Freelander jeep.
McCardle then lost control of the vehicle in Dundas Street, Edinburgh, and his vehicle mounted the pavement there.
It struck father of two Gavin Fulton, 43, who was heading to his home in the city's Claremont Bank. Moments after the collision, McCardle got out of his car and told a passer-by: "I killed him. I hit the guy and he's dead."
As police officers discovered that McCardle was almost two times over the legal limit, medics battled in vain to save Mr Fulton's life.
They rushed Mr Fulton to the Royal Infirmary. When he arrived at 2.45am, doctors found he had sustained brain damage, multiple spine fractures, collapsed lungs and an injury to an artery on his right arm that had caused internal bleeding. Doctors pronounced him dead at 6.40am.
McCardle, of Goose Green Place, Musselburgh, East Lothian, appeared at the High Court in Edinburgh yesterday and pleaded guilty to a charge of causing death by dangerous driving before judge Lord Doherty. The tragedy happened on December 8 last year.
Prosecution lawyer Leanne Cross told the court McCardle had gone out with his wife Donna for an evening at Bennets Bar in the capital's Tollcross area. They met Donna's sister and had a meal with drink.
At about 1am, they got into McCardle's car and he started driving, but after a short while he entered Dundas Street and hit Mr Fulton.
Onlookers saw that Mr Fulton was covered in blood. A cyclist called Gary Rose had stopped and heard McCardle say: "I killed him, I hit the guy and he's dead."
Police arrested McCardle and took him into custody. He gave two breath specimens, the lower of which had 63 milligrams of alcohol per 100 ml of breath - the legal limit is 35 milligrams.
He told officers that as he was driving through a green light at a junction someone stepped off the pavement from his left hand side. He said the man "had a grin on his face as if to say 'I'm not stopping'.
His statement to police said: "I swerved to the right hand side to avoid that person and managed to miss him, but then I lost control of the car."
Judge Lord Doherty deferred sentence until next month.
Speaking outside court after the hearing, Mr Fulton's father Bill, 73, paid tribute to his squash playing son and urged people not to drink and drive during the festive period.
Mr Fulton, a former manager with computer firm Hewlett Packard, added: "All I can say now is that the consequences of you risking drinking and driving are so dire, especially for the victim who gets a death sentence - that's a punishment our society deems too severe for the most vicious murderer.
"Gavin was a friendly, caring and helpful person whose life was dedicated to Jill, his wife, and Mia and Faye, his daughters. He was one of the pillars of our small family that can never be replaced.
"We are very relieved that the perpetrator has at last admitted his guilt. We can now only hope Lord Doherty delivers an appropriate sentence in line with the severity of the crime."