Police expect CCTV will help uncover who fired bullets near Crown Melbourne to end an early-morning argument.
Chief Commissioner Graham Ashton says the area around the casino is well surveilled by video cameras.
A gunman fired four shots at another man following an argument on Queensbridge Street about 4.15am.
But investigators have been unable to uncover any sign the other man was hit.
"It is not a random shooting. It certainly seems to be a targeted shooting. They have known each other in some way," Senior Sergeant Steve Bills told reporters on Thursday.
"It appears at this stage that the shots didn't hit the victim at all.
"We haven't had any contact with the victim and we would encourage the victim to contact police."
Police said the men walked off in opposite directions on Queensbridge Street after the shooting.
The shooting caused some upset for drivers in the area, with the scene on Power Street blocked off between Queensbridge Street and City Road for much of the morning.