Police said the crash happened in the Irving Park neighborhood's 4300 block of North Monticello Avenue at about 1:30 p.m.
Witness Cristian Garcia said the boy was walking with his mother, and was about to cross the street at Monticello and Montrose, when a black car went through the stop sign.
"It could've been much worse. He barely just took a step," Garcia said.
Police said it was a 29-year-old man driving the sedan northbound on Monticello Avenue when he struck the boy, who was crossing from the west side of the street.
"I see the kid got hit, and then my adrenaline started rushing. I see my little sister, so I was just devastated," Garcia said. "The mom was picking him up, and this whole thing was bleeding. It looked like he was like dangling sideways."
The man continued northbound, and other drivers followed behind him until he struck multiple parked vehicles a few blocks away at Monticello and Leland.
"I hear some screams, and I look out the window, and I see a car take off," Garcia said. "They went chasing after him."
Elmer Ambrocio's car was totaled.
"This is the only car that I have, and now, it's destroyed," Ambrocio said.
The driver then tried to get away again, this time, by running.
"So, a bunch of people in the neighborhood chased him down and tackled him. They were able to hold him until the cops came," said Randee Dewey, a witness.
The child was transported in fair condition to Lurie Children's Hospital for abrasions to his arms and knees, police said.
It was close call that ended with a community banding together to ensure the suspect faces charges.
"You obviously were doing something you shouldn't have done, and you made it so much worse," Dewey said.
Police haven't identified the suspect as charges against him are pending.
INTERACTIVE SAFETY TRACKER Track crime and safety in your neighborhood