Laird Hamilton -- RESCUES MALIBU SURFER ... No Lies Involved

Stop us if you've heard this one before -- a man risks serious injury to rescue a swimmer in distress ... only this time the story wasn't made up ... and the hero is the REAL DEAL.

It all went down Wednesday afternoon in Malibu -- where surfers flocked to the beach to catch some unusually large waves.

But when one surfer lost his board and found himself in trouble -- surf legend Laird Hamilton jumped into action ... grabbing his fins and racing out to the man to help bring him back to safety.

Laird was assisted in the rescue by another man.

We're guessing the mystery co-hero isn't a football player from USC.