WATCH: Beer deliveryman foils convenience store robbery in-progress

Credit this Coors deliveryman for staying “Rocky Mountain Cool” under pressure.

Brock Nulph was making his usual delivery at D&T’s convenience store in Enid, Oklahoma Monday morning when his routine day took a sudden turn.

That’s because a masked man was confronting the cashier near the front of the store.

“I asked him to get out of our store, or take the stuff off his face,” cashier Kristi Shiemann told KWTV News in Oklahoma.

“And about that time is when he held up the gun, or what I thought to be a gun.”

As the would-be robber hopped the counter, Shiemann grabbed her phone and a tazer and hightailed it to the back of the store – where Nulph was still unloading some cold ones.

“I see the guy coming around the counter and he looks at me, and just looks straight at the door,” Nulph said.

Nulph – who told reporters he has no history or training in either law enforcement or martial arts – grabbed the masked man by the arms, and slammed him to the ground.

“You have a split second to make a decision and that’s the one I made,” Nulph said.

For nearly five minutes, Nulph pinned the man to the ground waiting for police to arrive.

In that time, he learned that the man’s “gun” was actually just a black stick, and that the “man” was just 14 years old.

“I just hope this guy changes his life. He doesn’t need to be on this path,” Nulph told reporters after the incident.

As for Shiemann, she’s grateful that Nulph took such quick action to protect her in a crisis.

“Brock is my hero. I’ll tell that to the whole world,” Shiemann said.

The suspect’s name is not being released because of his young age. Police say he will be charged with armed robbery, possession of marijuana and tobacco, and possession of paraphernalia.