Police were notified of the shooting at 2:45am. Officers arrived at the scene, where they found blood marks on the floor near a table to the right of the stage.
Staff handed to police two 9mm cartridges they say were collected from the scene.
The victim, Pongwarit Tiptara, 27, had already been rushed to Patong Hospital.
Mr Pongwarit had been shot once in the leg and once in the back, with a bullet piercing a lung.
Mr Pongwarit was later transferred to Vachira Phuket Hospital in Phuket Town.
A friend of Mr Pongwarit who asked not be named told police, “When the pub closed, Mr Pongwarit and I were leaving. While we were leaving, the suspect and Mr Pongwarit bumped into each other.
“They just bumped shoulders, but they started staring at each other. Then the suspect took out a gun and shot Mr Pongwarit. They did not know each other.”
Police have named the suspect as Manus “Ta” Pongsupakit, 34.
“Ta used a white Honda Civic to escape. We are tracking him down through CCTV,” Patong Police Chief Col Tassanai Orarigdech told The Phuket News today.
“They did not have any conflict before this incident. The pub has been ordered closed for seven days while we continue our investigation.
“Manus faces charges of carrying a firearm in public and attempted murder.” Col Tassanai said.