Union City police Detective Gloria Hodgson said the gunman entered the Waffle House in Union City just before 2 a.m. Monday and demanded money, The Atlanta Journal Constitution reported Monday.
However, the alleged robbery was foiled when an armed customer shot the suspect, whose name has not been released.
The suspect was taken to Grady Memorial Hospital. His condition was not released by police.
Hodgson said there were no other injuries.