Jeff Probst definitely wants to bury his head in the sand on some far-away island … because he made a major mistake during last night’s live “Survivor 50” finale.

Spoilers ahead!!!

The longtime host totally blew it in a critical moment of the game … accidentally revealing the loser of the fire-making challenge … thereby making them the last castaway to take part in the jury.

Rizo Velovic was the castaway in question … and Probst let the cat out of the bag just as they were about to cut to a commercial — everyone stunned by the flub.

The poor host looked like a deer in headlights … realizing what he just did … and the show quickly cut to ads as he asked producers, “What just happened?”

Probst did his best to tell viewers how the mistake occurred … and tried to laugh off the moment … saying in part, “I love doing live television.”