Antonio Esfandiari prevailed in a daylong battle against Sam Trickett at the final table and claimed poker's richest prize of $18,346,673 on Tuesday night at The Big One for One Drop.
The $1 million buy-in tournament was the first-of-its-kind World Series of Poker event.
On the 85th and final hand, Esfandiari held on to win with three fives he acquired before the turn and overcame Trickett's flush draw.
Trickett, who had gone all in, nor Esfandiari were able to improve their hands during the turn and the river. Esfandiari finished with 143,975,000 chips.
"It's unbelievable," Esfandiari said. "It's euphoric. I'm so happy right now, and I don't even think it has set in."
Esfandiari and Trickett were the high stack twosome after Day 2 and remained ahead of their six opponents during the early stages of this three-day event at the Rio All Suite Hotel & Casino.
Esfandiari, of Las Vegas, also won a diamond and platinum champion bracelet. Trickett, of Britain, got $10,113,001. Eight players at the final table returned for the final day to split up more than $41,557,339.
Third-place finisher David Einhorn, a hedge fund manager from Rye, N.Y., said he plans to donate his entire prize of $4,352,000 to City Year, an education-focused nonprofit organization.
"It was fun," Einhorn said. "I mean you've got a poker tournament you put together with 48 terrific players. Most of them have lots and lots of experience, and then they invited a few guys like me in and said 'let's have a poker party.' "
Phil Hellmuth, who owns a record 12 WSOP champion bracelets, was eliminated in fourth place with a $2,645,333 prize. Trickett had an ace-high flush draw on hand No. 69 that put him in a position to win over Hellmuth.
Trickett earned his fourth career seven-figure tournament score. The only other players with four or more seven-figure scores are Michael Mizrachi, Phil Ivey and Gus Hansen.
Esfandiari, who was scheduled to be an analyst for ESPN for the three-day event, was the chip leader at the final table on the final day, with 39,925,000 (about 28 percent of the chips).
Trickett was closest to Esfandiari with 37,000,000 chips.
The event, which started with 48 players, will donate more than $5.3 million to international water advocacy charity One Drop.
The high-roller championship is the 55th of 61 events in the 43rd annual World Series of Poker, which started May 28 in Las Vegas.
More than 7,000 players are expected for the $10,000 buy-in no-limit Texas Hold 'em main event beginning July 7. It ends when the final table is reached July 16 and resumes with finals play on Oct. 28.