AN armed robber thought he had the upper hand when he burst into Cheryl Arnold’s office, held a gun to her head and demanded money, but the spunky great-grandma turned the tables on the criminal – by blasting him with a fire extinguisher!

“I got him good,” 72-year-old Cheryl told The ENQUIRER. “The stuff went all over him. It completely covered him.”

Cheryl, who manages the Vista Village apartments in Mt. Airy, a suburb of Cincinnati, Ohio, was working in her office on the morn­ing of Dec. 27 when the robber entered. He nudged her in the head with his weapon and told her to hand over the cash.

“I said, ‘I don’t have no money here.’ He said it again, and nudged me in the head with his gun again,” recalled Cheryl, who stands just 5-foot-3.

“Then he leaned over my desk and opened a drawer, but there was no money there. So he closed it and started to walk around the front of my desk.”

That’s when Cheryl reached for the fire extinguisher she keeps by her chair. Never leaving her seat, she pointed it at the gunman and pulled the lever.

“He was only about four feet away from me when I opened fire,” she said. “It’s got a lot of power and all this white powdery dust comes out and covers everything. It had to have hurt his eyes because I got him right in the face. Somebody told me that stuff really burns.

“All he wanted to do was get out of there. He ran out the door, rubbing his eyes and yell­ing. Somebody saw him running up the driveway and he was covered in white.”

Cheryl, who has eight children and “gobs” of grand­kids and great-grandkids, says the would-be robber probably figured there was cash around because people had just dropped off their rent money, but it was locked in a safe and she didn’t have the key.

The gutsy senior credits the guy who services the fire extinguishers at her job for recommending she keep one near her for defense since she didn’t want to have a gun in the office.

“I called his company afterward and thanked him because he really saved my life,” said Cheryl. “If I hadn’t had it, I don’t know what might have happened.”

Police are still searching for the gunman, who’s been described as a heavy-set young man wearing dark clothing.

Meanwhile, Cheryl has received a great deal of praise for her actions.

“People have congratulated me,” she said. “They’re sick and tired of all the crime we have, crooks thinking they can just take other people’s hard-earned money.

“They said it’s great that I gave one of them a taste of his own medicine.”