Two-time world poker champion Doyle Brunson has died at the age of 89, his family said Sunday.

"It is with a heavy heart we announce the passing of our father, Doyle Brunson. He was a beloved Christian man, husband, father and grandfather," the Brunson family said in a statement posted on Twitter by Brunson's agent, Brian Balsbaugh.

"We'll have more to say over the coming days as we honor his legacy. Please keep Doyle and our family in your prayers. May he rest in peace."

No cause of death was given.

Brunson, who was known as "The Godfather of Poker" and "Texas Dolly," won 10 World Series of Poker tournaments and was a two-time world champion with back-to-back wins at the World Series of Poker main event in 1976 and 1977.

Usually seen wearing his cowboy hat, Brunson made more than $6 million in live tournament earnings.

In 1979 he wrote one of the first books about poker strategy, "Super System," which is regarded as the bible of the game.

To his long-time poker opponent Daniel Negreanu, he was a "legend."

"There will never be another Doyle Brunson," Negreanu tweeted. 

"He will be missed by many, the Godfather of Poker."

Five-time WSOP champion Scotty Nguyen said he "can't believe this day has come."

"You will always be held high in our hearts, the man, the myth, the legend & THE GODFATHER of poker baby!" Nguyen tweeted. 

"Rest in Peace to the Biggest Legend of Them All. Thank you for being the consummate player and gentleman. No one will ever fill your seat," World Series of Poker tweeted.

Actor James Woods also paid tribute to Brunson, posting a picture on Twitter of himself with the poker legend.

"This one is a heartbreaker. Doyle Brunson, the greatest poker player who ever lived, has cashed in his chips," Woods tweeted.

"Doyle was so kind and helpful to me. He was gracious to my late dear brother and every friend I introduced him to. A gentleman and a genuine legend."

Born in Texas, Brunson played basketball at university but a knee injury ended his hopes of going professional.

Brunson was inducted into the Poker Hall of Fame in 1988.

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