Henry Cejudo is convinced his actions at a hit-and-run incident last week helped save the suspect’s life.

The wild scene, of course, all unfolded on Friday night in the UFC star’s Phoenix neighborhood … when he says he saw a group of young adults in a vehicle careening down his block at around 80 MPH.

Cejudo told TMZ Sports on Monday the car went airborne after it hit one of his neighbor’s sprinkler systems … and then it crashed through one of his other neighbor’s houses.

Cejudo said he grabbed the guy, threw him to the ground, put his hands behind his back and “slapped him a little bit.” He said the man should be grateful for it all, too, because he’s adamant if he hadn’t done what he did — his neighbors would have killed the guy.

Cejudo says two of his neighbors had guns on their person and they were ready to shoot. In fact, at one point, he says one of his neighbors cocked their firearm and screamed, “You move motherf****er, you’re dead.”

“If I wasn’t there,” Cejudo said, “this kid would have been dead.”

The suspect — later ID’ed by cops as 22-year-old Angel Cota — was ultimately taken into custody and booked on several charges … including DUI and assault.