A former professional boxer has been jailed for seven years for killing a stranger with one punch outside a pub.
Graham Brett, 50, pleaded guilty to the manslaughter of Australian-born Neil Hannah, 49.
Mr Hannah was felled with one punch to his jaw, which knocked him unconscious. He toppled backwards and suffered a brain injury.
He died five days later on August 7 last year, the Old Bailey heard.
Brett, of Ebury Bridge Road, Pimlico, central London, had been drinking in the Greyhound in Hugh Street, Pimlico, when he took exception to Mr Hannah and called him outside.
He took off his glasses and aimed a right hook at Mr Hannah, described as a "gentle giant" and "jovial drunk".
Brett, who had two wins and two losses in his career, and 70 amateur fights, had drunk seven pints and taken cocaine.
Gillian Etherton QC, prosecuting, said CCTV showed the incident.
She added: "It is very clear the stance the defendant takes is one of an experienced boxer."
Gareth Morley, defending, said Brett's career ended in 1984 and had been ravaged by his alcohol problem, although he was still a coach for amateur boxers.
Judge Mr Justice Stuart-Smith said three years of the extended sentence would be served in the community.
He told Brett: "You are a trained boxer. You used that training to position yourself and deliver the punch. This was an unprovoked attack."