According to the Douglasville Police Department, Williams tried to rob the Chevron at 6590 Bankhead Highway around 9:30 p.m.
An employee told FOX 5 the suspect barely came through the door, but pointed a gun at the clerk. When the man behind the counter looked up and saw the weapon, he pulled out his own firearm and shot the man once. Police said the clerk was not harmed.
"He did the right thing," said Harry Charles, who is a regular customer at the convenience store. "And you know what? I called [the clerk], too. I got his number and everything. I called him and he didn't pick up. I was worried about that. That's why I stopped by this morning, but I'm glad he's OK and he did what he had to do."
When police arrived on the scene, officers said they found Williams lying on the ground outside the store with a single gunshot wound. Paramedics transported him to a local hospital for treatment.
An employee said the incident left his co-worker shaken and that the clerk took Thursday off to recover.
"I'm glad he could defend himself because I probably know him and I wouldn't want to hear something tragic like that to happen," said Heavenly Jones, who lives near the store and stops by a few times a week.
Police said the clerk is cooperating with the ongoing investigation. At the point, the clerk will not face charges.