BIG BLOOPERS PUT KEN IN JEOPARDY!

Now Mayim's poised for kill

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JEOPARDY'S Mayim Bialik is gloating as her rival co-host Ken Jennings' snooty and snappish behavior turns off fans and bosses, insiders squeal.

After months of wrangling with the 48-year-old game show champ behind the scenes, a source says brainiac Mayim, 47, "has finally got the upper hand" to win total control over the late Alex Trebek's hosting gig.

For a while, "Ken managed to sway fans to his side, but now his bratty personality has taken over and he's making mistakes," spills a spy.