Police have released this CCTV footage showing a brutal and unprovoked attack in Nottingham.
The assault took place on Stoney Street, outside Bamboo Bar at 2.47am on March 1, 2015.
The victim appeared to be attempting to help a woman in distress when he was punched unconscious, suffering a fractured skull, reports the Notttingham Post.
The victim has been named as Michael Kane, who was visiting from Glasgow.
Detective Inspector Mike Allen said: 'This was an unprovoked and cowardly attack. So often we see one punch assaults like this end in tragedy.'
A second CCTV image shows the man, police are trying to trace, entering a bar.
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