Joe Cassidy described this hand on CardPlayer.com's streaming audio called "The circuit". It went something like this:

Patrick Antonius opened from cut-off position, and Cassidy called from the BB with A-7.

Flop came 5-6-9, two diamonds.

Cassidy checked, and Antonius bet about 80% of the pot.

Since Antonius had been playing very aggresively, Cassidy thought there was a good chance he had the best hand, and if he didn't he still had outs, so he called.

Turn came an offsuit Queen.

Cassidy checked, and Antonius checked behind.

At this point Cassidy didn't think Antonius had much of a hand.

River was a Jack, completing a possible diamond flush.

Cassidy bet out 140K to represent a hand, because he didn't want a small pair or a bigger ace-high to beat him in a free showdown.

Antonius raised to 340K, and Cassidy went into to tank.

Cassidy had the Ace of Diamonds, so he knew Antonius couldn't have the nuts. In the end he decided to call with the A-7 high because he didn't think Antonius would raise for value on the river since Cassidy called him on the flop and then led the river after the possible flush got there. He figured if Antonius had a strong hand there (flush, straight) he would just call and not risk getting re-raised by another big stack who could possibly have the nut flush. He figured the most likely reason Antonius raised was that he had a bluffing hand himself.

Sure enough, Antonius showed A-3, and Cassidy's 7 kicker barely beat the board to win the huge pot. A brilliant read on Cassidy's part.