CRIMESTOPPER’s TEXTBOOK  FAIL:  Jeopardy host ALEX TREBEK ruptures tendon after pursuing a hotel sneak thief who robbed him in the dead of night!
Trebek will undergo surgery for a snapped Achilles tendon he suffered while chasing a woman who broke into his hotel suite in San Francisco and robbed him early Wednesday.
Trebek, 71, was in San Fran to host the National Geographic World Championship at Google's headquarters in nearby Mountain View, California, reported.
Trebek and his wife were sound asleep in at the Downtown Marriott when he woke up around 3 am and spotted a woman  rifling  through his belongings.
As he gamefully gave pursuit, Trebek fell, snapping his Achilles tendon and injured his other leg.
The stolen items – purses and wallets – were found near an ice machine in the hallway.
Trebek told cops the thief also stole a bracelet of sentimental value, which remains missing.
After giving police a detailed description of the alleged perp woman and they nailed her.
The suspect — ID-ed by San Francisco police as Lucinda Moyers, 56 — was arrested on charges of felony burglary and possession of stolen property.
Police have “no idea” how Moyers broke into Trebek’s room.
Trebek, who's hosted Jeopardy! since 1984, will be in a cast for six weeks following the procedure.