A DJ was punched after a man asked to try on his Rolex watch outside a city centre bar, a court heard.
Sadieky Pridding-Bell, 27, threw a punch at the man outside Stage and Radio on Port Street in the Northern Quarter.
He then showed him a knife he had on him.
After the incident, Pridding-Bell, from Hulme, sent the DJ a message on Instagram saying he could 'expect to get his head blown off' if he reported it to the police.
Now Pridding-Bell has been jailed for 15 months.
Manchester Crown Court heard the DJ had been outside the bar for a cigarette at about 2am on February 15.
Another man made comments about his Rolex watch and asked to try it on, prosecutor Colin Buckle said.
He refused, and Pridding-Bell threw a punch at him.
Pridding-Bell stepped back and lifted up his top, showing the handle of a knife.
Shortly after Pridding-Bell left in a car.
Later that night, the victim received a 'threatening' message on Instagram from Pridding-Bell.
The victim replied to the message, saying 'do you think you can violate me?'
Pridding-Bell replied: "Yes I can."
The pair exchanged messages and talked about having a fight.
Pridding-Bell, of Chichester Road, Hulme, was arrested the following month.
He was remanded in custody and his lawyer Rob Kearney said he has served the equivalent of a 14 month sentence.
The defendant later pleaded guilty to three offences; common assault, possession of a knife and witness intimidation.
Sentencing, Judge Nicholas Dean QC: "This was an unpleasant incident.
"The seriousness of it was you showed the victim a knife.
"That in my judgement was a private exchange and did not risk serious disorder in Manchester city centre."
The judge said witness intimidation is a 'serious matter', and it 'attacks the confidence of the public in the criminal justice system'.
Judge Dean said Pridding-Bell, who has committed 21 previous offences, is 'perfectly capable' of being a 'decent, honest, upstanding member of society'.
