A local singer was performing at Uncle Giuseppe’s Marketplace in Ramsey when he suddenly began to suffer a massive heart attack.

Thankfully, one of the shoppers was a former EMT who came to the rescue.

In the middle of a performance on Saturday, Russell Martorana experienced one of the most life-threatening events, a heart attack leading to cardiac arrest.

A store manager told News 12 he had fallen off the stage during the attack and hit his head, which was bleeding.

William Kelly Jr., a former EMT, happened to be in the checkout line when he heard someone call for help.

"I've seen this many times in my volunteer career and I was convinced that this was not going to have a good ending,” Kelly said.

But Kelly's training kicked in and he sprang into action to help Martorana.

"I did what I was taught to do and initiated CPR immediately and directed some people to get the AED, call back 911, tell them it was cardiac,” Kelly told News 12.

He performed CPR until medics arrived, which he says became tiring, but he was the only one around who knew how to do it, so he kept going until paramedics arrived.

Martorana was taken to Valley Hospital in Paramus. His wife and two daughters rushed to his bedside when they found out.

"Once all the crazy confusion calmed down, we were desperate to know who the guy was," says Martorana's daughter, Nicole Beniamini.

She and her sister took to Facebook to search for the man who saved their father's life to thank him and reunite the pair.

"You saved a good person. My dad saved somebody during 9/11, he saved his sister who was choking,” Beniamini said, adding, "I told him, 'You earned a guardian angel on your own shoulder.'"

Kelly even gifted Martorana with a new microphone for his future performances.

Martorana's family says they're forever thankful to the man in the checkout line, who was just minutes away from leaving the grocery store that day but turned around to help a stranger instead.

Martorana is now expected to make a full recovery. Doctors and nurses are calling it a miracle.