It happened around 4 a.m. Saturday near State and Chestnut.
The 41-year-old victim was shot in the abdomen during an argument over a parking spot.
Witnesses were stunned by the violence in that neighborhood.
"I'm shocked," said witness Samuel Kavziela. "It's the Gold Coast, it's happening here. I'm shocked. The other guy basically went back, took a gun. I saw him walking out with a gun and he just shoot the other guy and then all three of them took off."
The victim was taken to northwestern hospital in serious condition.
The gunman fled in a white car.
Police are investigating and no arrests have been made.