There was "mayhem" outside a flat Harry Baker had stayed at in the hours before he was fatally stabbed, a court heard.
People were "jumping in and out of windows" and someone "was trying to kick the front door in", in Barry, neighbour Timothy Windsor told a jury.
Another neighbour told Newport Crown Court how she was "slapped" in the face with a machete by a man waiting to ambush Harry.
Six men and a boy deny murdering Harry, of Cardiff, in August 2019.
The victim's body was found with nine separate knife wounds, in a shipping container yard in Barry Docks.
Leon Clifford, 23; Raymond Thompson, 48; Lewis Evans, 62; Ryan Palmer, 34 and Peter McCarthy, 37, all from Barry, deny murder.
Leon Symons, 22, from Ely, in Cardiff, and a 17-year-old boy who cannot be identified also deny murder.
Referring to the night of 28 August, 2019 outside the flat, Mr Windsor said the events are "always in my mind".
Five or six people were outside, with "loads of effing and jeffing outside, loads of people, it was just mayhem", he told the jury.
He said "they were jumping in and out of the windows all the time" and "someone was trying to kick the front door in".
Witness Natasha Allt told jurors she had been "terrified" when she was "slapped" in the face with the machete by defendant Mr Symons, as the masked and armed group lay in wait for Harry, in a hedge.
She described how Harry and a friend were ambushed before the pair were chased to Barry Docks.
The court also heard that as Harry walked around the corner near her home she heard one defendant shout "there he is, that's him".
Some of the defendants then ran over to Harry and pulled out their knives, she said.
Ms Allt said Harry and his friend also pulled out knives and the group was "jousting a little".
'Harry advertised drugs'
Referring to the police statement she later gave, she said she heard someone say, "You dead men, you think you can take over but you can't".
Asked in court who had said it, she replied, "that would be Leon Symons".
Seconds later other people arrived at the confrontation and Harry and his friend "took off running" and were chased.
The jury has heard Harry asked crack users to "advertise" his drug dealing.
The prosecution has suggested he was killed because he and a friend were selling crack and heroin on "turf" that was not theirs.
The trial continues.