A teenager murdered a nightclub reveller minutes after being seen brandishing a knife following a "trivial" altercation on the dance floor, a court has heard.
Kobe Murray, aged 19, plunged a blade into the heart of amateur footballer Ryan Passey after a second incident which at worst involved punches being thrown, Birmingham Crown Court was told.
Opening the case against Murray, prosecutor Phil Bradley QC said Mr Passey was pronounced dead in the early hours of Sunday August 6 after being stabbed at the Chicago's club in Stourbridge, West Midlands.
Murray, who denies murder, is alleged to have stabbed Mr Passey after the incidents, which happened minutes apart and began when a man squeezed another man's bottom.
a knife and believed the defendant was trying to show it to him.
Mr Bradley added: "The prosecution case, members of the jury, is that it was a knife and Kobe Murray was preparing himself for further trouble.
"Immediately after the stabbing, Kobe Murray fled the club, attempting to hide his face from CCTV cameras as he did so."
Murray, of The Broadway, Dudley, was driven back to his home by a friend after allegedly showing him a blood-stained knife, which was dumped in undergrowth.
On the afternoon of August 6, Mr Bradley said, Murray phoned his mother, telling her he had "messed up" and done something really stupid.
Murray's father then collected him from Tipton and drove him to West Bromwich police station, where he surrendered to officers.
During an interview on August 7, Murray chose not to answer police questions but presented a statement through his solicitor claiming he had been attacked at Chicago's.
The pre-prepared statement ended: "If I used a knife it was in self-defence. I do not recollect the exact circumstances due to being attacked and being intoxicated."
Addressing the issues being put before the jury, Mr Bradley told the panel: "There is no suggestion that Ryan Passey or anyone in his group was armed with a knife or other weapon.
"It is against this backdrop that Kobe Murray's use of a knife should be measured.
"You may think that taking a knife to an unarmed man falls well short of reasonable or proportionate."