The shooting caused pandemonium in the packed mall as shoppers evacuated.
Video from the scene shows shoppers running for cover.
Watch: Pandemonium At The Mills At Jersey Gardens Mall After Shooting
The gunman remains at large.
Investigators say the victim won’t tell them whether he knows the man who shot him, or why they were fighting.
Police say surveillance footage also shows two groups fighting when the gunfire broke out.
The mall reopened Saturday, with a special lost and found for people who left items behind.