Ryan Riess emerged with the title after a session in which he started behind, but used expert skill to gather the chips to his side amid the unpredictability of no-limit Texas Hold 'em.
Riess put his final opponent Jay Farber all-in with an Ace-King.
Farber, a Las Vegas club promoter, had been fighting for his tournament life for several hours. With just 14.2 million in chips to Reiss' 176.5 million, Farber made his stand with Queen and 5 of spades, only to run into Reiss's Ace and King of hearts.
It wasn't looking promising, but he had a chance — that is until the flop came four-Jack-10. That meant a Queen now would make a straight for Reiss, so only one of the three remaining fives in the deck could help Farber. Neither the fourth nor the fifth community cards brought any help, and Reiss was champion.
Reiss backed into the stands to watched the cards turn, and won the championship with the arms of a girlfriend around his shoulders.
His fans immediately tackled him to the ground.
Moments later, he accepted the diamond-encrusted championship bracelet.
"I want to thank my family and my friends, they're the best friends in the world," he said, his voice choked with tears.
Asked how such a young player came in with so much confidence, he said, "I just think I'm the best player in the world."
Marc-Etienne McLaughlin of Brossard, Que., finished sixth. He earned $1,601,024.
Farber said he plans to keep his day job, despite the $5.2 million second-place haul, and added that all the publicity would be good for business.
The men started the night at the 1,600-seat theatre at the Rio All-Suite Hotel & Casino off the Las Vegas Strip walking onto like prizefighters, with showgirls looking on and a UFC announcer introducing Riess as "Riess the beast" and Farber as "the panda."
After starting 19 million chips ahead with 105 million, Farber was down to 15 million two hours into the night, which he pushed all in before doubling up, and starting a minor comeback.
Riess seemed to both outplay Farber and catch a streak of better cards as the night began. He traced his fingers in small circles on the green felt, and gave Farber occasional wan smiles. His fans, a collection of clean-cut men in white "Riess the beast" T-shirts, chanted and stomped each time the boyish players with a mop of strawberry blonde hair used his chip advantage to go after Farber.
On the club promoter's side, stylish guys with tight T-shirts and slick hair under fuzzy panda hats called out taunts about bankrupt Detroit, and mocked Riess' youth, height and messy hair.
Riess' side called back that pandas are delicious, referencing the "combat panda" symbol Farber has adopted, settling a mini-stuffed animal on the green felt and bringing along a plush mascot who was kicked out for disorderly behaviour Monday but returned with a bit less swagger Tuesday.
Both sides watched with fists pressed to light lips as Farber's fortunes plummeted.
The winnings they were competing for— a sparkling bracelet and $8.4 million in cash — sat between them on the table like a third player.
Riess, Farber and seven other finalists beat out a field of 6,352 entrants in the no-limit Texas Hold 'em tournament in July. On Monday night, Riess eliminated four competitors with a sly, steady playing style, and Farber took out the other three with more straightforward, aggressive plays.
A VIP club promoter with heavily tattooed forearms and a bouncer's build, Farber has said he considers poker a hobby. Some are calling him a new-age Chris Moneymaker, after the amateur who famously won poker's richest tournament in 2004, catapulting the championship into the mainstream and convincing every computer nerd with a pair of mirrored sunglasses that he could take on the pros.
Riess began to seem like an underdog Tuesday night, despite his chip advantage, as observers from the ESPN commentators in the theatre to Twitter pundits around the world gushed about his opponent's unconventional backstory and supposed ability to usher in a new golden age of poker.
Farber had the benefit of counting some of the world's best poker pros among his friends, some of whom may have a claim on the pile of money sitting on the table underneath the blue and red glare of television lights.
Farber says he sold stakes in his championship bid because the $10,000 entrance fee was too much to put up by himself. He said he kept a significant part of his own action, though he wouldn't say whether he'd kept a majority. Now his investors stand to win about $840,000 for every thousand they put in.