ATLANTIC CITY, N.J. - A gambler at an Atlantic City casino has won $1 million on a $20 poker bet.

The woman, whose name was not disclosed, won the amount early Sunday as part of the "Three Card Poker 6 Card" bonus jackpot while playing at Harrah's Resort Atlantic City.

The promotion offers gamblers various cash prizes if they draw a royal flush. The payouts they receive depend on the amount they bet and whether their royal flush occurs in diamonds, hearts, spades or clubs.

Casino officials say the woman had been playing at the table for about two hours when she got a royal flush in diamonds , the promotion's top payout.

It marked the second time that a gambler has won the $1 million payout since the promotion began Sept. 26.