Two men are credited with springing into action and saving a critically wounded Suffolk County police officer following an altercation. 

Police say the situation started when a car was stopped for allegedly driving erratically with its headlights off in Patchogue. They say Jonathan Nunez, 25, of Centereach, was behind the wheel at the time.

Despite attempts to stop the car, police say it kept going, and then at the corner of South Ocean Avenue and Brook Street, investigators say Nunez hit another car, jumped out and ran into the backyard of Guillermo Sandoval, who saw the situation unfold.

Police say Nunez got into a fight with the officer, pulled out a knife and stabbed him in the thigh. Medical officials say the officer sustained life-threatening injuries when he was stabbed, as it hit major arteries in his leg.

The PBA identified the injured officer as Christopher Racioppo, a three-year veteran of the force.

Retired NYPD officer JR Recupero saw the crash and ran to help.

"The police officer had the Taser on him. I seen the dot and almost simultaneously the officer goes down," he says.

Recupero then tackled Nunez, not knowing where the knife was.

"I was trying to hold his arms, the officer is yelling, 'I got stabbed,'" he says. "'Where's the knife? I'm going to get stabbed,' lock up his arms, don't let him move."

Recupero says he then saw how seriously the officer was hurt, and says he heard him say he was losing consciousness.

Sandoval, a former Marine, came to help as well. And when he heard the officer calling for help, he says his combat training kicked in.

"I went upstairs grabbed a belt and ran back out, started putting the tourniquet on him at that time, other officers ran in and helped out," says Sandoval.

The officer was rushed to Stony Brook University Hospital, where he underwent emergency surgery.

A doctor says the officer would have died if the artery that was severed had not been controlled within 20 minutes. The use of the tourniquet was hailed as an important step.

The doctor added that steps taken in the aftermath of the incident leave him hopeful that the officer will be able to make a full recovery in use of his leg.

Racioppo remains in critical condition and is receiving "minute-to-minute" care 

Suffolk PBA officials say if it wasn't for the homeowner and Recupero, their officer might not have survived.

Noel DiGerolamo, Suffolk PBA president, released a statement saying, "We ask all of the Suffolk County residents to continue keeping Officer Racioppo in their thoughts and prayers as he remains in critical condition struggling for his life. Once again, we are forever indebted to Dr. Vosswinckle and Stony Brook University Hospital's entire staff for giving him a fighting chance."

Suffolk Executive Steve Bellone called Racioppo a "hero" in a Monday afternoon news conference

"We do know what he stopped that night ... we don't know what lives he may have saved, and we'll never know because he took action, because he did the right thing," says Bellone.

As for Nunez, he was been charged with aggravated assault upon a police officer, DWI and resisting arrested. He is in a hospital and will be arraigned at a later date.