With Nguyen leading Gordon Vayo by about 100 million chips in their final showdown, Vayo drew Queen-9 and landed a "fantastic" flop of 9-4-2.
Knowing he was sitting on a good chance to win - an 82 per cent chance, to be precise - he checked, hoping to draw more money out of his opponent.
He did, with Nguyen hoping for something to complement his Jack-5.
As the turn came, he realised he was losing the battle. Probably knowing that he was holding a worse hand, Nguyen started bluffing - hard. Really hard.
He threw in almost 28 million more chips trying to scare Vayo away, but Vayo didn't cave. He called again. The pot is 89 million chips at this point with one more round of betting.
A five fell on the river; Vayo has literally a 100 per cent chance to win the hand at this point, and has succeeded in drawing a good chunk of cash from Nguyen.
Until Nguyen goes all in with a 0 per cent change to win.
An incredible bluff that spikes the pot to 162.2 million chips and leaving Vayo totally lost.
After minutes of deliberation, Vayo folds. Nguyen's aggression turned a certain loss into a giant win with an all-time bluff.
"I'm out of words," said the commentator.