Austin Metcalf was helped by immediate responders right after he was stabbed by Karmelo Anthony ... who can be heard begging him to stay alive and performing CPR until paramedics arrive in shocking 911 audio.

The audio captures the crowd's initial reaction to Metcalf fighting for his life at an April 2025 high school track meet in Frisco, Texas ... with a man calling 911 and informing a dispatcher of the incident.

At first this man tells the dispatcher Austin doesn't appear to be breathing ... though he later changes course and says the teen was able to gather some air -- but that he wasn't conscious.

The caller says an Army veteran is trying to keep pressure on Austin's chest wound ... while in the background of the call, a man loudly tells Austin to stay with them.

Later, the group surrounding Austin is heard performing CPR ... with someone repeatedly yelling "Fight through" and "Come on, Austin," trying to will him back to life.

Despite the best efforts of these Good Samaritans, Metcalf was taken to a local hospital where he ultimately died. Anthony was arrested for -- and eventually convicted of -- his murder.

This 911 audio was released along with other videos important to the case ... including body cam footage which shows Anthony sobbing to cops -- and insisting Metcalf put his hands on him.

His lawyers claimed Anthony acted in self-defense at the track meet during his trial ... but the jury ultimately convicted him anyway.