A would-be thief who tried to grab a 22-year-old mother's iPhone at a Bronx laundromat punched the woman's 6-year-old son in the face when the boy stepped in his way as he tried to flee the mother's grasp, authorities said.

The man walked into the laundromat on Boone Avenue in Crotona Park East shortly before 5 a.m. Sunday and tried to sell the woman DVDs. She said she wasn't interested in buying any, and the man grabbed her iPhone, which was charging on a chair next to her, authorities said.

The suspect tried to run off with the phone but the woman grabbed him, trying to keep him there. He managed to break free with the phone and started running toward another exit when the 6-year-old boy stepped in his path.

Police say the suspect punched the young child in the face, knocking him to the ground, before running out to the parking lot. The boy's mother chased the suspect outside and wrestled her iPhone from the suspect before he managed to break free and ran off again.

Surveillance video shows the mother chasing the suspect back and forth across the laundromat (above).

The woman suffered minor injuries in the altercation and her 6-year-old son had facial swelling and lacerations. Both were treated at an area hospital.

"I really can't imagine a grown man punching a 6-year-old in the face," said Luis Rodriguez, a patron at the laundromat. "That's horrible."