A teenager who learned CPR weeks earlier at school, put the live-saving techniques to use on an unconscious woman in a Walmart parking lot.

Ethan Shean, 16, went to the store with his friend Vincent Casarez to get bread on Dec. 1 when they saw the woman on the ground, a baby and another woman nearby calling for help, according to the Messenger Post.

"My immediate thought was, 'What do I do?,'" Shean told the Messenger Post on Tuesday. "I don't know what's going on. Is this real? Is this something I need to be helping with?" He heard the victim's friend repeat, "What do I do? What do I do? She's not moving, she's not breathing."

Shean started doing chest compressions and the woman’s friend started to administer mouth-to-mouth breathing.

The woman regained consciousness and her friend took her to the hospital.

That was the first and last time the teens saw the victim, her friend and the baby.

“I felt, wow. I just did this and just changed this lady’s life. It was shocking, but exciting,” Shean said. “I couldn’t just stand there and do nothing, so I just did something. It feels pretty good. I’m glad I did what I did, and I’m glad I had my friend there to witness everything.”