There’s no question: Nancy Zerg is America’s new quiz whiz.

In a finale that went down to the final question and was decided by a one-dollar margin, Ken Jennings, 30, lost the “Jeopardy!” episode aired Tuesday to the 47-year-old real estate agent from Ventura, Calif.

TV’s winningest quiz show contestant by virtue of a 75-episode run that saw him defeat 148 opponents, Jennings entered Final Jeopardy with $14,400, Zerg with $10,000.

The Final Jeopardy clue was: “Most of this firm’s 70,000 seasonal employees work only four months a year.”

Zerg smiled as host Alex Trebek revealed her correct answer, then her wager – $4,401, bringing her to $14,401.

Trebek turned to Jennings and revealed his answer: “What is Fedex?” Incorrect.

Trebek studied the math and announced, “He winds up in second place.

“And Nancy Zerg you are a giant killer!”

Jennings hugged her. The audience gave a standing ovation.

Zerg returns Wednesday night to “Jeopardy!” while Jennings appeared on a whirl of interview shows – ABC’s “Nightline” and CBS’s “David Letterman” among them.

And Wednesday, as an ex-champion, he can begin to figure out what to do about his $2,520,700 winnings. He may want to seek advice from a firm whose 70,000 seasonal employees work only four months a year:

H&R Block.