Cada made what experts call a 'nearly impossible comeback' before winning the World Series competition today.
World champion: Joe Cada, a 21-year old poker professional from Michigan, poses with his $8.5m winnings
He dodged elimination several times during the longest no-limit Texas Hold 'em main event final table in history, at over three hours.
He battled 41-year-old logger Darvin Moon and at one point held only one per cent of the chips in play.
He told reporters: 'Luck always helps. I'll take all the luck I can get.'
The player was virtually unknown when he started the competition, but he is now worth approximately £5.1million.
Chips on the table: Joe tosses in chips during the game against Darvin Moon, a 45-year-old logger from Maryland
The finale pitted the youthful professional - who makes a living playing poker online - against a self-employed logger who, until this year's World Series of Poker, had never been on an airplane or gambled for high stakes.
Before the match, Moon said: 'They say he's some kind of specialist online. But I'm not online to watch.'
Cada's record-breaking win breaks a record for the tournament's youngest winner set last year by 22-year-old Peter Eastgate of Denmark.
The previous youngest winner, Phil Hellmuth, held the record for over two decades. He was 24 when he won for the first time in 1984.
Spectators watch Joe Cada (who appears on the big screen) during poker battle
The crowd of supporters erupted as Cada played his winning hand, and got ready to claim the cash as his